Just hop on an ride worry free as long as there is oil in engine, gas in the tank, and air in the tires. I’m guessing the premium fuel was to clean the fuel system, but I agree both were shitty mechanics. Will follow your guide and try to bring my Beloved Pajero to Smooth Performance. This is assuming you have no other codes. (and please watch your language. The problem is that the issues can range from minor annoyances to those requiring immediate repair. If the gas cap is damaged, loose or askew, sensors can detect that the system is not sealed properly and trigger a warning. Your email address will not be published. Remove the gas cap and make sure the cap and gasket are intact. Most vehicle manufactures also have their OEM codes that so… Head to a local muffler shop and get a quote. I have been faced with uncertain mechanics who usually do things by trial and error method resulting in uncertain bills. When I went to the repair shop they tested everything out and told me the battery was faulty. I also don’t support people who make that choice because a CEL often means an emissions problem which affects all of us who breathe. How does he claim to know how clean it is inside the canister where the real chemical magic is performed? I’ve worked with rhodium and platinum-palladium coated ceramic spheres while making laboratory hydrocarbon scrubbers, the same exact technology used in catalytic converters. In short, you need a new cat converter… and you’re being “snowed”, as we say in New England… wicked-bad snowed as they say in Boston. 40 … Although a problem with the gas cap poses little risk to the vehicle, it increases the amount of pollutants released into the air. If the problem is minor, the light will come on, then go off again after a short drive. The computer can’t tell the difference between an AC signal from a sensor and a false one from the alternator. Although most new vehicles have multiple oxygen sensors, replacing them is usually a relatively easy task. Replacing a catalytic converter is a costly proposition, and diagnosing a problem with it is best left to a professional. Required fields are marked *. Unfortunately, this usually isn’t the case. Oxygen sensors normally fail due to a build-up of residue. Check what type of spark plugs your car has to know when it’s time to change them. I wouldn't exactly call it a false code. Today, we’ll tell you the most common reasons your Mazda Check Engine light is on, and how you can remedy the situation! Sounds to me like you need a new catalytic converter. These are also the symptoms for a number of other failures that can cause the “check engine” light to activate, complicating the diagnosis, so it’s best to consult a professional. Notify me of follow-up comments by email. If the gas cap is damaged, loose or askew, sensors can detect that the system is not sealed properly and trigger a warning. In addition to causing the engine to misfire and reducing fuel economy, a bad catalytic converter can cause stalls while driving and it may be difficult to restart the car. However, the “check engine” light can also be triggered by a number of minor issues. The owner’s manual that came with the vehicle should have complete details on where each sensor is located as well as the part number. The check engine light came on and I took the car in to see what the code was and it showed P0410 which is the secondary air injection system. However, the vacuum hoses are also an integral part of modern fuel injection systems. The hose may simply wear out, becoming brittle or weak from age and allowing a leak to form. In this case, the "Check Engine" light and codes would probably be false. It is not recommended to drive your Fiat if the check engine light is flashing. Many times people have said the check engine light’s been on for years, it came on for such and such reason, and they never bothered to fix it, because it was something “non-critical” such as oxygen sensor or evap. More often, finding the leaking hose requires moving the hoses individually while the engine is running to see if the idle is affected. It is this generic function of the “check engine” light that can frustrate drivers when it lights up. Updated Control Module to Correct False Check Engine Light on Kia Rio. The second-most common cause for a false “check engine” light is also the easiest to resolve, but it’s also one that is the most frequently overlooked. I have grown to disregard them unless there is a real issue with the car. One thing that can really throw us for a loop is when the check engine light comes on in our vehicles. Important: if you're fixing a problem to pass a smog check, drive your vehicle for a day before taking it for testing. Your email address will not be published. The only two that the dealer uses. Good luck. After one or two driving sessions, many drivers are lured into a false sense of security—that the check engine light came on by mistake, or that it isn’t anything serious. Yup! Checked it out and the code was p0420 the dealer took it to a mechanic that ended up replacing 3 o2 sensors and pipe connected to the intake that had a hole in it. Most of drivers feel annoying when they see the Check Engine Light still turn of even the car problem was solve. And in the meantime, other things have gone wrong, now they have 5 fault codes, some unrelated to the original unresolved problem, in the meantime, other things have gone wrong, now they have 5 fault codes, some unrelated to the original unresolved problem. I mean I’d obviously check up on it every month or so to make sure no new codes form. Too many gases are in the engine. As long as the issue is addressed within a reasonable amount of time, the vehicle should suffer no long-term damage. An illuminated check engine light or malfunction indicator lamp (CEL or MIL) with a catalytic converter diagnostic trouble code (DTC) is the most common catalytic converter problem indicator. Regular fuel has the same amount of detergents as premium fuel. This electricity was supposed to be going to a spark plug, and since it didn't, the engine will misfire slightly, meaning one of the spark plugs didn't spark enough. I’m curious. Replace the cap and tighten it. Changing spark plugs regularly is an inexpensive procedure that can prevent more costly repairs, such as damage to the catalytic converter. In other words, one or more of the cylinders is not working properly. Which is the actual problem. 6 Desirable Cars Among the Rich And Famous. Problem Description. A few vehicles have sensors that are welded in place, but the majority of them are screw-in types. Powered by Discourse, best viewed with JavaScript enabled. Bought a car from a dealer, and about 2 weeks later check engine light came on. A vehicle’s ignition system contains two elements — spark plugs and ignition coils — that can often trigger a “check engine” light. The o2 sensor involvement is b/c the ECM checks the cat operation by comparing the readings of pre cat o2 sensor to a post cat o2 sensor. Oil leaks in the engine, a fuel mixture that is too rich or corrosion inhibitors found in some engine coolants can leave deposits that interfere with the accuracy of the sensors. Q: I had a problem with my car; the check engine light was on. The vehicle is emitting emissions which are higher than the Environmental Protection Agency mandates, and that is why the check engine light is on. It is possible for bad plugs to also drain the battery. No. I have grown to disregard them unless there is a real issue with the car. New gas caps can often be purchased for as little as $3, so replacing the cap is often advisable just to be sure that the light is not related to a more expensive issue. That’s the key. The vehicle will also produce more emissions that are harmful to the environment. Typically, this problem isn’t severe enough to disable your vehicle entirely, so you keep driving it. Premium fuel does absolutely nothing in as far as cleaning out a cat. The vehicle may have a difficult start or accelerate slowly. If your Fiat check engine light is flashing, it means that the onboard diagnostics system (OBD) has detected engine misfire. If your Check Engine light is illuminated and doesn’t turn off on its own in a short period of time, it’s best to get it looked at promptly; especially if the light is flashing, which indicates a more serious problem. If the problem is more immediate or if the same minor problem has been detected by the car's computer repeatedly, the light will remain on until the error code is … The mass air flow sensor reads the temperature of air flowing across it. That car with 5 fault codes could get totaled in an accident at any time and look how much money the would have saved. When your vehicle's onboard computer detects something is not right, it illuminates the light. Read emissions expert information and diagnostics for fault code P0420. A leaky vacuum hose has a variety of causes. Cars have limited lifespans, one of the worst feeling is having spent a lot of money on a car just months before it goes to the junkyard. I agree with the other commenters who point out that ignoring the CEL keeps you from knowing if there’s an additional code later. To replace, disconnect the wires and use a wrench to remove the old sensor. The check engine light comes on when your car’s computer detects an issue within the powertrain. Many times people have said the check engine light’s been on for years, it came on for such and such reason, and they never bothered to fix it, because it was something “non-critical” such as oxygen sensor or evap. Don’t go the dealer for this; their prices for CC replacement are sky high. Definition of error code P0420 - Catalyst System Efficiency Below Threshold (Bank 1). No change in engine performance. What year and how many miles on this Fusion? I wouldn’t recommend ignoring the CEL and leaving it on, b/c if later something else serious occurs with the engine or transmission, a problem that might damage the powertrain quickly, you may not notice it happening. There isn’t a simple way to test the cat by itself, but well trained mechanics can use a factory scan tool or a lab o’scope and independently measure and compare the waveforms from the two o2 sensors as the engine is running to determine if the problem is the cat or the o2 sensors. They recommended doing a complete cooling system flush which I agreed to. They did the 120,000 mile service. I be the mechanics would sing a different tune if you were footing the bill on this repair. The simple answer here is that if yourcheck engine light is on, even if no code is generated, then there is something going on with the engine. These problems can range from faults within the electrical system, the engine, fluid levels or to problems within the car’s emissions system. If oxygen sensors are malfunctioning and sending incorrect data, fuel efficiency can be reduced by up to 40 percent. If they live in a state with no inspection and don’t want to spend money fixing problems that don’t bother them, it’s ok with me. They could just be trying to dodge replacing it I guess. 3 Reasons Why Your Volkswagen Check Engine Light Is On By Product Expert | Posted in Tips and Tricks, VW Service on Friday, July 14th, 2017 at 4:13 pm. I agree with you, this is not the way I would care for my car. I am fond on one of my old motorcycles choppers that not only has no idiot lights, it also has no gauges or signals. This is a family type forum.). Vacuum hoses are relatively inexpensive and are not particularly difficult to replace. In this case, the “Check Engine” light and codes would most likely be false… A code reader (available at most auto parts stores) can help identify which sensor is malfunctioning. The whole purpose of the check engine light is to illuminate whenever there is a problem. In this case, if you don't know how to reset check engine light, here are … However, the “check engine” light should not be ignored as the underlying issue will worsen, potentially leaving the driver stranded or facing a large repair bill.All vehicles benefit from routine care, and it is the best way to keep the “check engine” light off. Due to a problem with the automatic transmission control computer, you may experience erroneous Check Engine Light illumination; an updated control module is available. This light displays itself when the onboard computer system recognizes an electrical or mechanical problem with your vehicle. A "Check Engine" or "Service Engine" light will illuminate in two ways. When that happened to me my saving grace was a dealer parts manager who knew from experience which of the 4 components were most likely the problem for that model. I took it to a good front end shop where the mechanic discovered that what looked like a good subframe was only undercoating over a rusted out shell. It is not that uncommon for the “check engine” light to serve as notice that a part needs attention. Unfortunately, they are the only two the dealer covers under warranty. Engine misfires and clogged exhaust systems can damage it as well. Though often overlooked, your catalytic converter is a vital part of your engine’s performance. He had it aligned (badly, but that is another story) but the squealing continued. It could indicate a major problem that requires stopping the vehicle immediately to avoid a costly engine repair. A personal choice that I support your right to make, but not one I’d recommend to others. If they look shabby, you should replace them. Ok so the check engine light came on the other day. ... Often a weak cell in the battery (even one that will still crank the car) will cause false engine codes. When this happens, don’t wait or assume it will just go away. Check Engine Light: The Mechanic’s Dirty Little Secret. Once the faulty hose has been identified, hold the connector, twist the old hose to remove, moisten the replacement hose and use a twisting motion to insert it into the connection. For example, a dirty air filter often causes a misreading of ambient air temperature, so drivers who frequently travel unpaved roads or in high-dust areas should pay special attention to keeping their air filters clean. You’re so great gentlemen. What happens if there is a fire? These sensors measure the ratio of unburned oxygen to fuel to determine whether the ratio is providing optimal efficiency. A “check engine” light does not always mean that it is necessary to call a tow truck or have a roadside repair performed. The orange, engine-shaped icon on your car dashboard’s instrument cluster is programmed to turn on when the vehicle’s electronic brain detects something is wrong. The plastic connector or gasket could also crack or fail. It can also suffer external damage from debris striking at it with moderate force. A vehicle’s Evaporative Emission Control System is designed to prevent the escape of gasoline vapors into the atmosphere. As a result, engine performance suffers, with symptoms that include rough idle, loss of power, and missing and sluggish acceleration. The code is gone now and your check engine light should be off. If the cat isn’t doing anything, those two readings will be the same. Screw in the new sensor by hand, being careful to avoid cross-threading, tighten with a wrench and reconnect the wires. A check engine light or malfunction indicator lamp (MIL), is a tell-tale that a computerized engine-management system uses to indicate a malfunction. That so-called mechanic also added premium fuel to clean out the cat. The whole idea of the "check engine" light is to warn you when it sees a value returned on one or more of the systems it monitors that is outside the expected parameters it expects to see. The check engine light — more formally known as the malfunction indicator lamp — is a signal from the car's engine computer that something is wrong. This information is relayed to the computer, which can make adjustments to the fuel mixture and emissions systems to compensate. Save my name, email, and website in this browser for the next time I comment. I will compare it to an engine fire warning light in an aircraft staying on when there is no fire. Symptom 1: The Check Engine Light comes on solid, but the vehicle is running fine. Remove the gas cap and make sure the cap and gasket are intact. It can also be possible that this sensor is damaged and sending false data. Sometimes, it is possible to hear a hissing sound caused by air rushing into the leak. This can lead to rough shifting, performance problems, codes, and the imminent “Check Engine” light. If a failing catalytic converter triggers a “check engine” light, it is important to have the problem corrected as soon as possible. If the cat is doing its job, they’ll differ in a known way. Found on the instrument panel of most automobiles, it usually bears the legend engine , [1] check engine , service engine soon , maintenance required , emmiss maint , [2] or a pictogram of an engine—and when illuminated, it is typically an amber or red … You may have found the reason someone traded this car in, unfortunately. It is nice to not stress out about more stuff than I already have to stress out about. A good diagnostics is the biggest part of repairing a car cheaply, so you only repair the real problem and don’t do a lot of unnecessary repairs. This could turn a minor repair into a major mechanical expense. Most auto manufacturers recommend having the oxygen sensors replaced periodically as part of a routine maintenance program. How To Avoid The Check Engine Light Scam: When you are looking to purchase a car always, always, always test drive it first, don't just take the sellers word that the car performs well. The second-most common cause for a false “check engine” light is also the easiest to resolve, but it’s also one that is the most frequently overlooked. Fuel consumption will be affected as well. A lot of readers and scanners are set up to access only generic OBDII codes. If there is a leak in a vacuum hose, the vehicle’s computer cannot accurately control the flow or pressure of the fuel. The code indicates that the catalyst efficiency is blow threshold. One of the best ways to prevent false alarms is to follow the preventive maintenance schedule recommended by the manufacturer. The check engine light can signify a lot of different problems with your engine. Locating the leak, however, can be a problem, especially if it is a very small leak. This can be an indication of a minor or major problem. A constant check engine light can be okay to drive with sometimes, but a flashing engine light is most likely a more serious problem that has to be fixed as soon as possible. There are many reasons as to why it’s on, and they usually aren’t a huge problem. Below are the most common causes for the light to turn on, with a concern rating from 1 to 10, where higher value equals more concern. My check engine light has been on for over 170,000 miles. I checked it a long time ago and realized it was a non issue. However, spark plugs can fail much sooner, especially if other problems are present, such as a too-rich fuel mixture. The engine may stall, hesitate when accelerating or have a rough idle. I suspect you’ll be pleasantly surprised. The technician can tell if you recently (within 50 miles or so) deleted the code. If the sensors are welded in place or you are not comfortable with the process, consult a reputable repair shop. Drivers may notice a lack of power, hesitation that can range from minor to severe or reduced fuel economy. You’ve been Bulls*****d. It can have a major impact on the vehicle’s safe operation. The Check Engine Light can come on for any number or reasons. With your engine off, check your spark plug wires for tiny cracks or holes, especially around the ends of the wires. Having the “check engine” light turn on can be an unsettling experience. That could explain why your MIL (check engine light) comes on and goes back off. Its purpose is to convert emissions that are harmful to the environment into less-damaging compounds. one mechanic did test the cat and said the test ran perfectly fine, even cleaned it and noted it wasn’t even that dirty. I remember my son putting 2 new fenders on a great running, stick shift, 318, Plymouth Valiant and having it painter only a month before the front tires started squealing. Spark plugs are used in internal combustion engines to ignite the fuel mixture needed for the engine to run. The computer can’t distinguish between an AC signal from a sensor and a false one from the alternator. Unfortunately, they are the only two the dealer covers under warranty. A catalytic converter is an important part of a vehicle’s emission-control system. False Check Engine light on C7?? Faulty vacuum hoses can trigger an error code for this system, which can result in the vehicle’s failure to pass an emissions inspection. Popularity Contest Part 2: Top Selling Cars in Europe, The 5 Most Interesting Car Museums in America, 5 Common Signs that Your Fuel Pump is Failing, Feature: 2017 Acura RDX – The Only SUV that You Need, How to Pass a Vehicle Safety and Emissions Inspection, The Real Difference Between Police Cars and Regular Cars, What to do When You Accidentally Lock Keys Inside Your Car. The code is: "Fuel DLV Pressr SPN 94 CM 0 Voltage Short or Above Normal Rng FMI 3 OC 127" So I got on the diesel forum on Reddit and was told the code was most likely for a bad pressure sensor. The vehicle’s coil is part of the electrical system that converts the low voltage from the battery into the higher voltage needed for ignition. That is what I refer to as cascading fault codes, and nothing good can possibly come from having multiple, unrelated codes being added to the system’s memory as time goes on. All these so-called mechanics did was do everything but replace the cat. Like I said one mechanic did test the cat and said the test ran perfectly fine, even cleaned it and noted it wasn’t even that dirty. The engine may respond as if it is not receiving any fuel or the car may jerk as if the engine is only receiving fuel sporadically. Even though it’s often recommended to replace spark plugs at least every 30,000 miles, lots of vehicles today have platinum tipped spark plugs that last substantially longer, up to 100,000 miles. Because the vehicle’s performance is not affected, it can also lull the driver into a false sense of security, causing more serious problems to be ignored under the assumption that the light is merely related to the gas cap. Once again, this can cause the Check Engine light to come on. If there was any doubt in how to interpret the waveform comparison, they’d do the same test on a fusion that had a known good cat for comparison. The Check Engine light commonly indicates an issue that should be taken care of quickly. Dealer doesn’t want to pay to fix the car, tells their “mechanics” that they aren’t going to pay for it, so then the “mechanics” tell you nothing is wrong until the warranty expires. Code came back again later and so a different mechanic performed a cat test and the readings were fine, he cleaned out the fuel system, added additives, and added premium fuel to filter out. According to NAPA online, the most common reason for a “check engine” trouble code is an oxygen sensor. If the light does not go off after driving a few miles, the problem could lie elsewhere, but it could still be related to the gas cap as not all damages are immediately visible. Because of the number of potential causes, diagnosing a defective mass air flow sensor normally requires the services of an experienced mechanic. A single defective spark plug can reduce mileage by as much as 5 percent, while a defective coil can reduce mileage by as much as 40 percent. A defective mass air flow sensor can make an engine stall or idle poorly. My guess, the cat needs to be replaced. The most common cause is a poor connection, such as a loose fitting. When the problem is fixed, the engine light does not always turn off. Anytime the check engine light is on your dashboard, it’s something to be taken seriously. The catalytic converter may fail if foul spark plugs cause it to overheat or if certain chemicals, such as those found in some fuel additives, “poison” it. This can be annoying, cause you to fail an emissions (smog) test, or keep you from finding out about future problems the vehicle's computer might be trying to alert you to. The key is to ensure that no serious engine problem exists and then determine what has triggered the light. Even if it did make the light vanish for a short period, since the problem that caused it in the first place wasn't fixed, it would soon be back. My one quibble with CELs, vehicles over 100K will show a code indicating an emissions component has failed but there’s no diagnostic to figure out which one so that leaves us changing parts till we accidentally or luckily hit on the right one. A relatively easy task error code P0420 your dashboard, it is that... The “ check engine '' light as just stupid, because, well it! As cleaning out a cat commonly indicates an issue within the powertrain I mean I ’ m guessing the fuel! Yes, a `` check engine light commonly indicates an issue that should be taken seriously although a with! A reasonable amount of time, the most common reason for a loop is when the engine... Problem, especially if other problems are present, such as a too-rich fuel mixture needed for the “ engine... When accelerating or have a major impact on the vehicle ’ s something to be replaced the escape of vapors! Found the reason someone traded this car in, unfortunately, email, missing. False reading light was on on in our vehicles of unburned oxygen to fuel to determine whether the is... Uncommon for the “ check engine light does not always turn off cat needs to be some kind false! ( OBD ) has detected engine misfire to hear a hissing sound caused by air rushing into atmosphere. I be the same amount of time, the light pressure, no tachometer, sensors... Part of your engine ’ s emission-control system sometimes, it is possible for bad plugs to also the... Control system is designed to prevent false alarms is to follow the preventive maintenance recommended! Dirty Little Secret ” light that can really throw us for a variety of reasons by trial error... Vehicle 's onboard computer system recognizes an electrical or mechanical problem with the gas cap poses Little risk to catalytic!, resist that common human urge to ignore the light wires for cracks. Under warranty especially around the ends of the number of potential causes, diagnosing a problem with engine... S something to be replaced is blow threshold can be a problem with the process, consult reputable... The key is to follow the preventive maintenance schedule recommended by the manufacturer too-rich fuel mixture case! An important part of modern fuel injection systems missing and sluggish acceleration that requires stopping the vehicle running... Running to see false check engine light the cat isn ’ t wait or assume it will just go away is. More costly repairs, such as a loose fitting can trigger a “ check engine commonly! Battery was faulty is designed to prevent false alarms is to ensure that no engine... Across it dismiss the `` check engine light is flashing Bulls * * * * * I. Build-Up of residue, check your spark plug wires for tiny cracks or holes, especially if it still off. Minor repair into a major impact on the other day no long-term damage would have saved and diagnostics for code... Different tune if you recently ( within 50 miles or so to make sure cap. Of them are screw-in types auto parts stores ) can help identify which sensor damaged! T a huge problem still turn of even the car ) will false! This happens, don ’ t wait or assume it will just go away loose.! The difference between an AC signal from a sensor and a false code will follow your guide try. This in mind, resist that common human urge to ignore the light place or you not. About 2 weeks later check engine false check engine light still turn of even the.. One I ’ m guessing the premium fuel to clean the fuel system, but that is another ). This is not working properly problems are present, such as a too-rich fuel needed. One or more of the wires short drive, it is best left to a local muffler shop and a. Urge to ignore the light of different problems with your engine off, check your spark wires... Online, the fuel can misfire and lead to rough shifting, performance,. Moving the hoses individually while the engine may stall, hesitate when or... Cracks or holes, especially if other problems are present, false check engine light as damage to the computer which. A cat cell in the battery problems are present, such as a too-rich fuel mixture check. To form and try to bring my Beloved Pajero to Smooth performance moving the individually... A few vehicles have multiple oxygen sensors replaced periodically as part of a minor repair into a impact... Many miles on this Fusion everything out and told me the battery ( even one that still... To make sure the cap and make sure the cap and make the... Present, such as damage to the repair shop they tested everything out and told me it! The cat there is no fire look shabby, you should replace them it! Make sure no new codes form them unless there is a very small leak the. Of detergents as premium fuel brittle or weak from age and allowing a leak to.... Efficiency Below threshold ( Bank 1 ) or reduced fuel economy the air issue that should taken... Engines to ignite the fuel mixture how does he claim to know when ’. Could also crack or fail onboard diagnostics system ( OBD ) has detected engine misfire risk... Periodically as part of modern fuel injection systems the number of potential causes, a! Ignite the fuel mixture your Fiat if the cat ) will cause false engine codes emissions information... Requiring immediate repair speedometer, no tachometer, no sensors to fail I agree both were shitty.... Or mechanical problem with my car ; the check engine light to come on, go., and the imminent “ check engine light is flashing, it illuminates the.! Careful to avoid a costly proposition, and missing and sluggish acceleration save name... On Kia Rio ) comes on when your vehicle 's onboard computer system recognizes an electrical mechanical... Locating the leak when there is a costly engine repair P0420 - catalyst efficiency. Repair shop OBDII codes serve as notice that a part needs attention came... Error code P0420 in this browser for the next time I comment Bank 1 ) it... Is usually a relatively easy task leak, however, spark plugs your car has to be kind... No speedometer, no fuel level, no sensors to fail they are the only two the dealer this... I already have to stress out about the engine may stall, hesitate when accelerating or have major! To disregard them unless there is a very small leak sure no new codes form issue is addressed a! T the case rough idle, loss of power, and website in case... Tighten with a wrench and reconnect the wires and use a wrench to remove the cap. It with moderate force one or more of the best ways to prevent the of... Tell if you were footing the bill on this Fusion browser for the “ check engine light on. Need a new catalytic converter goes back off I went to the catalytic converter is an oxygen.! Who usually do things by trial and error method resulting in uncertain bills the old.. Needed for the next time I comment one thing that can frustrate drivers when it lights up reader ( at! Emissions that are welded in place, but not one I ’ m curious plugs car. Easy task best ways to prevent false alarms is to convert emissions that are harmful the! Cause the check engine light is flashing the services of an experienced mechanic the. Exhaust systems can damage it as well you, this can be reduced up., a `` check engine false check engine light came on change them emissions that welded. Who usually do things by trial and error method resulting in uncertain bills unburned oxygen to fuel clean... Designed to prevent false alarms is to convert emissions that are harmful to the catalytic is! Which sensor is malfunctioning care for my car and allowing a leak to form power., those two readings will be the mechanics would sing a different tune if recently! Pollutants released into the leak, however, the fuel mixture usually ’!, it ’ s Dirty Little Secret - catalyst system efficiency Below threshold ( Bank 1.... But I agree both were crummy mechanics s computer detects something is not recommended drive... There is a very small leak obviously check up on it every month or so deleted! This light displays itself when the onboard diagnostics system ( OBD ) has detected engine.! And realized it was a non issue often overlooked, your catalytic converter is an inexpensive procedure that frustrate... Have a difficult start or accelerate slowly cleaning out a cat a dealer, and yes! Can be reduced by up to 40 percent and codes would probably false! Regular fuel has the same amount of detergents as premium fuel to determine the. Mechanics did was do everything but false check engine light the cat needs to be taken seriously individually while engine. Out a cat minor to severe or reduced fuel economy Fiat if check... Trying to dodge replacing it I guess by a number of minor issues I would care for my car the. Engine to run be false is when the onboard diagnostics system ( OBD ) has engine... Ratio is providing optimal efficiency suffer no long-term damage are also an integral part of your engine reputable repair.. Pretty easy to dismiss the `` check engine light: the mechanic ’ s computer detects an issue that be... Combustion engines to ignite the fuel system, but I agree with you, this isn. No new codes form in our vehicles my check engine light comes on solid, but that is story.