For many people, the “check engine” light is one of the most dreaded maintenance issues in a vehicle. This is because the problem can’t be diagnosed without an experienced mechanic and the cause could end up costing more than you’d want to pay. If your “check engine” light is on, don’t wait too long to take your vehicle in to a mechanic; if the light is blinking, we recommend you make an appointment as soon as possible.
The Oxygen Sensor
The most common reason a “check engine” light will go on is because of a faulty oxygen (O2) sensor. Over time, this sensor can accumulate oil ash and when enough is accumulated, it can’t read how much fuel is being burned. A faulty sensor will not only reduce your gas mileage, but it will also increase your emissions.
Average repair cost: $250
A Loose/Faulty Gas Cap
If your “check engine” light is on and you recently filled up your gas tank, check your gas cap. A loose or faulty gas cap can trigger the light and can be easily fixed by re-tightening the cap or by replacing it, if needed.
Average repair cost: $0-$30
The Catalytic Converter
A vehicle’s catalytic converter is what turns carbon monoxide into carbon dioxide and it can fail over time if you don’t replace old spark plugs or a broken O2 sensor. With a bad catalytic converter, you may notice a decrease in gas mileage or a decrease in acceleration when you push down the gas pedal.
Average repair cost: $1,500
Things like bad gasoline, not replacing your fuel filter, and debris (from constantly running your vehicle with a near-empty fuel tank) can clog up your fuel injectors. When this happens, they fail and your vehicle may have trouble running (or may not run at all).
Average repair cost: $550
The Mass Airflow Sensor
The Mass Airflow Sensor (MAS) measures the amount of air flowing into your engine and adjusts the engine’s fuel intake accordingly. If the MAS is faulty, you may experience decreased gas mileage, stalls, and increased emissions. Also, if it’s not fixed, the faulty MAS could damage your spark plugs, O2 sensor, or catalytic converter.
Average repair cost: $300
Ignition Coils/Spark Plugs
Ignition coils are what ignite your spark plugs to start your vehicle and if either of these things are faulty, it could cause misfires or jolts in acceleration. Additionally, the problem could be related to the spark plug wires.
Average repair cost: various