5 Problems That Will Turn on Your Check Engine Light

The check engine light is there to protect your European automobile and you. It illuminates when there is a problem that another dashboard warning light does not cover. In some cases, the problem is simple and you can fix it yourself. In other cases, you might have a failing part that can damage your engine. TRUE Automotive can determine why your check engine light came on. Here are five possibilities.

Too Much Carbon Monoxide

A fuel-driven engine produces carbon monoxide; it’s a natural byproduct of burning fuel. To prevent excess carbon monoxide in the environment, automotive engineers designed catalytic converters. When the catalytic converter fails, it cannot convert your engine’s carbon monoxide waste into the much-safer carbon dioxide. Consequently, your check engine light will come on to alert you of danger.

Too Many Gas Fumes

If your vehicle’s gas cap is old and cannot seal anymore, your onboard computer won’t like it and it will turn on the check engine light. The gas cap is designed to seal off the gas tank so fumes stay inside and fuel doesn’t evaporate. Old gas caps can lose their seal, or you may have just screwed the cap on wrong when you stopped for gas. Check your gas cap if you get a dashboard warning.

Air Imbalance

There’s a part in your European vehicle’s engine called the mass airflow (MAF) sensor and it measures the air coming into the engine. You wouldn’t think air could be a problem but it can. Too much or too little air will affect your engine’s performance. In fact, it could even prevent you from starting your car. An MAF failure will cause an air imbalance and, you guessed it, a check engine warning.

Oxygen Imbalance

The same holds true for oxygen, which is monitored by the oxygen sensor. Oxygen is released in your vehicle’s exhaust, and if the oxygen numbers aren’t right, your automobile will fail an emissions test. The oxygen sensor has a limited lifespan, usually about 100,000 miles, after which it can go bad. When this happens, you end up with too little or too much oxygen in your vehicle’s exhaust.


Finally, starting and running your engine requires a host of things to happen, including the spark plugs firing in the right order. Old and worn spark plugs often misfire, i.e. they fire out of order or don’t fire at all. This will affect your engine’s performance and turn on the check engine light. If can’t remember when it was you had your spark plugs changed, it’s probably time to change them.

We are TRUE Automotive and we are European automobile specialists. Call our Marietta, GA, shop at 770-214-4688 to schedule a service appointment.

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