
Everyone wonders what to expect when their check engine light comes on. Many people know it can be an issue costing a hundred dollars or upwards of a thousand.
According to CarMD.com the most common causes are faulty oxygen sensors. This and other problems can be costly to ignore; one or lots of little problems can snowball into large costly repairs. Not replacing a faulty oxygen sensor can cause spark plugs to foul out and not replacing fouled out spark plugs can cause ignition coils to fail.
The five most seen check engine light trouble codes will reduce gas mileage. After we have considered the oxygen sensor, the top reasons for you check engine light to illuminate are:
- Defective ignition coil(s)
- Defective spark plug wires-These can fail simply over time or due to fouled out spark plugs.
- Loose gas cap-This is the most common reason for a gas evaporation code or other codes related to cause a check engine light to illuminate. This can result in a significant loss in fuel and fuel economy.
- Defective the mass air flow sensor-The MAF sensor reads the mass of air being introduced into the engine in order to determine how much fuel should be added to the mixture for the best combustion ratio. When this part fails, you can be adding an unnecessary amount of fuel or not enough, neither of which is good for your car or your wallet.
- Defective the catalytic converter-A catalytic converter usually won’t fail unless another component is not working correctly, usually because of large amounts of fuel going through the exhaust. A damaged converter will cause excessive exhaust back pressure which will result in a loss in fuel economy and can eventually completely clog up, possibly damaging other exhaust components and/or causing a crank/no start condition.
There are dozens of other reasons for your check engine light to illuminate, but the one rule that holds true with almost all malfunction codes is that if they are put off you will be paying for it in either more extensive repairs or a loss in fuel economy, or in most cases both!