Almost as scary as seeing the red flashing lights of a police car in your rear view mirror, is the sudden appearance of a red or orange warning light on the instrument panel of your car…especially when it’s flashing. The check engine warning light is one of the most dreaded and confusing aspects of owning a vehicle. It’s just an ominous light that offers little or no information as to what the problem is…and seems to appear with no logical warning. But there are a few things you can do yourself to pre-diagnose…and possibly fix yourself…before dragging yourself to the repair shop for a financial flogging.
Unless your car starts smoking or stalls completely…head over to a service station and have them run a diagnostic to find the cause of the check engine light. Call ahead and make sure they can handle your make and model, since some cars have special computers. Once you’re at the shop, they’ll come out and plug a small computer underneath your dashboard and read back a code stating what happened to the car.
5) Bad Spark Plugs & Wires
The spark plug provides a gap for a spark to jump across and initiates combustion in your engine all while sealing the combustion chamber. When the plugs are failing, the spark plugs misfire. You’ll feel a little jolt in your car’s acceleration when this happens.
Causes: Most spark plugs in cars from before 1996 should be replaced every 25,000-30,000 miles. Newer ones can last up to 100,000 miles. Still, plugs fail over time and there’s not much you can do about it.
What to do: Get them replaced right away. It’s easy and cheap and your car will run better for it. If your spark plugs fail and you’ve made your way to the auto parts store, you can replace them easily following the video above. Since this is part of your vehicles regular maintenance, the spark plugs are usually easily accessible from the hood of the car. It’s simple enough that I’ve seen people doing this in the auto parts parking lot on several occasions.
4) Bad Mass Airflow Sensor
The mass airflow sensor tells the car’s computer to add the proper amount of fuel based on the air coming through to the engine. A faulty one can increase emissions, cause the car to stall, and decrease gas mileage.
Causes: Most mass airflow sensors fail because of a improperly installed (or never replaced) air filter. You should replace the air filter at least once a year to help prevent the airflow sensor from failing.
What to do: Theoretically you can drive for a few weeks or even months with a broken MAF sensor. You will notice a decrease in gas mileage and over time the car will eventually start stalling a lot. At a shop, the replacement cost is between $200-$300 depending on the car, but that’s usually the cost of parts because the labor is relatively simple. It’s not terribly difficult to do on your own, but the process is quick enough you may want to let a mechanic handle the project in case the sensor doesn’t end up being the issue.
Plenty of other possibilities for a check engine light are out there, but the above five are the most common. How long do you usually let the check engine light stay on before you do something about it?
3) Bad Catalytic Convertor
The catalytic convertor works to reduce exhaust gases. It converts carbon monoxide and other harmful materials into harmless compounds. If your catalytic convertor is failing, you’ll notice a decrease in gas mileage or your car won’t go any faster when you push the gas.
Causes: Catalytic convertors shouldn’t fail if you’re keeping up on regular maintenance. The main cause of failure is related to other items on this list, including a broken oxygen sensor or deteriorated spark plugs (we’ll get to those in a second). When it fails, it stops converting carbon monoxide into less harmful emissions.
What to do: If your catalytic convertor fails completely, you eventually won’t be able to keep the car running. Your gas mileage will also be terrible, so you should try and fix it as soon as you can. Unfortunately, the average replacement cost is around $2,000 and you can’t do it yourself unless you’re an experienced mechanic.