Why is my check engine light coming on?

While an issue as minor as a missing gas cap can trigger the check engine light, when the light does come on, you'll still want to take it seriously and get to the shop for computerized diagnostics. This way, any developing issues can hopefully be nipped in the bud and save you from much more costly repairs. Here's a look at seven reasons that the check engine light turns on.

Failing Catalytic Converter

The catalytic converter turns carbon monoxide into an emission that is less polluting. Dark exhaust smoke and poor acceleration are two signs of catalytic converter trouble.

Faulty Oxygen Sensor

Oxygen sensors monitor the quantity of unburned oxygen in the exhaust system. An oxygen sensor issue can lead to problems with the catalytic converter.

Bad Battery/Charging System

If a failing battery causes low voltage at the computer, then the check engine light may illuminate.

Failing Spark Plugs

Old, dirty spark plugs can cause a reduction in performance and gas mileage. As a general guideline, spark plugs in older vehicles should be changed every 30,000 miles. For vehicles made after 2000, you can often go 100,000 miles before replacement is necessary.

Faulty Mass Air Flow Sensor

Mass air flow sensors keep tabs on the amount of incoming air and calculate how much fuel to inject with it. An indication of a mass air flow sensor problem is that your engine stalls soon after you fire it up.

Poorly Fitting Gas Cap

Though it might seem strange, a loose or missing gas cap may trigger the check engine light, while also allowing gas to evaporate before you get the opportunity to use it.

Faulty Ignition Coil

Ignition coils play an important role in generating the spark that the engine needs to fire up on all cylinders. Signs of ignition coil trouble include misfiring and power loss.

If you need check engine light diagnostics and repair, be sure to visit a reputable auto shop. For diagnostics and engine repair in Corona, Eastvale, and Norco, CA, contact the experts at Harvey's Autotech at (951) 432-5373. Feel free to give Harvey's Autotech a call today to schedule an appointment for any of your vehicle's repair or maintenance needs!

Harvey's Autotech Blog
Posted: September 1, 2020

Written and Published By MORBiZ