2023 Top 10 Check Engine Light-Related Repairs According to CarMD.com

CarMD.com released its annual study of check engine light-related repairs for 2023. Not surprisingly, catalytic converter replacement and oxygen sensor replacement made the top of the list – the high cost of precious metals makes catalytic converter theft a lucrative pastime. The oxygen sensor often gets damaged during theft, hence it’s 2 nd position on the list. Here is the list with additional information about the components on the list:

Catalytic converter replacement – with no moving parts, catalytic converters rarely fail. A vast majority of catalytic converter replacements are due to theft.

Oxygen sensor replacement – oxygen sensors often are damaged during catalytic converter theft.

Replace ignition coil and spark plugs – as the overall age of vehicles on the roads increases, we see more need for ignition coil and spark plugs replacement.

Replace mass air flow sensor – most vehicles have a hot wire MAF sensor, which consists of a heated wire and a wire kept at ambient temperature. Repeated heating and cooling can be one of the reasons for MAF failure.

Ignition coil replacement – ignition coils generate the high voltage that allows the spark plug to create the sparks that ignite the fuel-air mixture. As the vehicle ages, one or more ignition coils may need replacement.

Replace EVAP canister purge control valve – the purge control valve is typically located between the fuel tank and the intake manifold. Controlled by the powertrain control module, its function is to allow fuel vapors from the EVAP canister to flow into the engine – this helps to reduce emissions and improve fuel efficiency. Valves are electro-mechanical devices, and as all mechanical devices are likely to fail with age.

Tighten or replace the fuel cap – a faulty fuel cap is the hoped-for condition when the check engine light comes on. It’s a surprisingly frequent cause of the check engine light being illuminated.

Replace ABS wheel speed sensor – wheel speed sensor can fail due to clogging from brake dust, metallic debris, or dirt, and exposure to harsh elements. Age increases the probability of sensor failure.

Replace fuel injector – two frequent causes of fuel injector failure are bad fuel quality, which can clog the fuel injector, or the injector may develop a crack or a leak. Again, age increases the probability of fuel injector failure.

Reprogram powertrain control module – reprogramming may be required to resolve emissions or drivability issues, and is a necessity whenever the powertrain control module (PCM) is replaced.



This list of the top 10 check engine light–related repairs should not be considered a substitute for a professional check engine light diagnosis and repair. At Toole’s Garage, we highly recommend getting your vehicle to a friendly local mechanic as soon as possible if the check engine light becomes illuminated. Call us to make an appointment, or make an appointment online on our website.