Top 5 Reasons a Check Engine Light Comes On

Seeing your vehicle's check engine light come on can be disturbing. Most of the time the engine light will illuminate for something simple. The only way to find out is to have the car read by a diagnostic machine. There are several common reasons the light can come on.

A cars check engine light is designed to illuminate when there's a problem. Unfortunately, the light doesn't tell you what the actual problem is. There are several reasons it can come on. In most cases it will be one of the reasons listed here, and can be a simple fix.

Gas Caps

As car manufacturers try to make their vehicles smarter, small problems can become big. Having a loose cap is one of the most common reasons a check engine light comes on. Check to make sure the gas cap is secure and isn't damaged. If you have to replace it you should be able to do it for under $50.

Oxygen Sensors

When an oxygen sensor wears out the check engine light will illuminate. This sensor essentially tells the car if the fuel is being burned correctly by measuring the exhaust. Replacing this sensor is more expensive, but considering how much car repairs are it's not that bad. In most cases it will be less than $200.

Air Flow Sensor

The mass air flow sensor (or MAF sensor) is one of the more common reasons this light can come on. This sensor measures the air that makes it into the engine. It will cost around $400 to replace, but this fix will help increase power and acceleration.

Bad Spark Plugs

Bad spark plugs are another common reason the check engine light may come on in your car. This job can usually be done at home for under $50, but some cars require a specific tool and a mechanic.

Catalytic Converter

This common reason is also an expensive one. When the catalyic converter in your car goes bad the engine light will come. You're also looking at a repair that can soar over $1,000 to repair.