Check Engine Light

Reasons Why Your Check Engine Light Has Illuminated

Your car’s Check Engine Light (CEL) illuminates when your car’s computer senses that something is amiss.  When it illuminates it is rarely an emergency but it’s something that you may wish to bring to a mechanic to evaluate as soon as possible.  Here are the top reasons why a CEL light goes on:

Oyxgen Sensor needs replacing 

The most common car repair when the CEL illuminates is dealing with a faulty oxygen sensor. The O2 sensor is important to a car’s engine performance.  O2 sensors can fail prematurely for a number of reasons but usually it’s just a matter of age. When ignored, a faulty O2 sensor may result in a 40-percent reduction in gas mileage.

The Evaporative Emissions (EVAP) Purge Control Valve needs replacement 

The Purge Control Valve is another component of your car’s EVAP system.  When the car’s engine is fully warmed up, the main CPU module slowly opens the purge valve to allow some of the fuel vapor to be sucked from the charcoal canister. Then, that fuel vapor is burned in the engine.

Spark Plug Wire(s) and Spark Plug(s) issues 

Faulty spark plug wires and/or spark plugs may cause a “misfire,” reducing gas mileage.  If this is the problem that is happening, then you likely need to replace the spark plugs and wires.

You Need a new Mass Air Flow Sensor

The mass air flow sensor measures the air enteringthe car’s engine and works with the main CPU to determine how much fuel to inject into your engine. When the mass air flow sensor isn’t working right, fuel economy will usually drop and the engine will run rough.

You Need One or More Engine Coils

Ignition coils give high voltage to your spark plugs. Many conditions, including high engine bay temperatures and age, can result in engine coil failure.Car owners should pay special attention since ignition coil failure damages the car’s catalytic converter.

The thermostat needs replacing 

The thermostat regulates the engine coolant temperature in the engine block/radiator system. When a thermostat goes bad, it often gets stuck open. If the vehicle’s computer doesn’t see the engine coolant temperature go up to operating temperature within a certain time period, it will illuminate the CEL. The solution is to replace your thermostat. This is what needs to happen according to Patrick Jaguar of Naperville, a full-service car dealership in Naperville, IL.

Tighten Your Fuel Cap 

Believe it or not, the fuel cap has to be tightened in order for your car’s EVAP unit to function right. If your CEL light ever comes on, the first thing to do is check that your fuel cap is on tightly.

The Catalytic Converter needs replacing 

Hopefully you never have to replace a catalytic converter because they are quite pricey.  In many cases, a catalytic converter won’t fail unless a misfire occurs, which may be caused by ignoring a faulty ignition coil, spark plug or engine mechanical issue.

In case this every happens to you, or if it has happened, we hope this article has been helpful. The bottom line, though: if your CEL illuminates, have a mechanic look at it.