Are You Wanting to Know What Causes the ‘Check Engine’ Light to Come On?

Most vehicle owners know that if they want to keep their current car a reliable source of transportation, it is important to take good care of it. Even with regular engine service, it is possible for the “Check Engine” light to illuminate on the instrument panel. This often brings on anxiety as they wonder what causes the “check engine” light to come on? A vehicle owner’s biggest fear is that they will end up spending thousands of dollars for a major engine repair.

Calm your fears! The “Check Engine” sensor is a part of the on-board diagnostic system, constantly monitoring engine performance, such as engine speed (RPMs), air to fuel ratio, and ignition timing. If a “fault” is detected by the sensor, whether big or small, the “check engine” light will illuminate, alerting you that there is a problem that should be taken care of.

So what causes the “Check Engine” light to come on, you wonder? Here are five of the most common problems:

1. Damaged Gas Cap – If the gas cap is loose or cracked, fuel vapors leak out and can throw the whole fuel system off, reducing gas mileage and increasing toxic emissions. Tightening or replacing the gas cap may resolve the problem.
2. Faulty Oxygen Sensor – The oxygen sensor monitors the unburned oxygen from the exhaust, along with how much fuel is burned. A faulty sensor doesn’t send the right data to the computer, reducing gas mileage and increasing emissions.
3. Failing Catalytic Convertor – The catalytic convertor reduces exhaust gases by converting carbon monoxide and other harmful materials into harmless compounds. If it fails, your gas mileage will decrease and you will feel a loss of power when you try to accelerate.
4. Faulty Mass Airflow Sensor – This sensor tells the car's computer to add the proper amount of fuel based on the air coming through to the engine. If this sensor fails (the air filter may be clogged), toxic emissions will increase, your car may stall, and gas mileage will decrease.
5. Dirty Spark Plugs and Wires – The spark plug provides a gap for a spark to jump across and initiates combustion in your engine. If the spark plugs are starting to go bad, replacing them is an easy fix.

A word of advice: Following the engine service schedule will help prevent engine problems from turning into a costly engine repair.

Do you have more questions about what causes the “Check Engine” light to come on? Contact our ASE Certified Technicians at B & L Auto Service (Toledo Auto Care) in Whitehouse, OH, for more information about engine repair and to schedule an appointment. Our auto shop is proud to serve vehicle owners in Whitehouse, OH, and the surrounding areas.