What are common reasons the check engine light comes on?

What are common reasons the check engine light comes on?


While an illuminated check engine light doesn't necessarily mean that you're on the cusp of engine failure, it's still best to bring your vehicle to the shop for computerized diagnostics. By being proactive about identifying the issue, you can potentially address it before it worsens and becomes much more expensive to fix. Here are seven common reasons the check engine light turns on.

Failing Catalytic Converter

To turn carbon monoxide into a less polluting emission, you need a healthy catalytic converter. Poor acceleration and darkened exhaust smoke are signs of a catalytic converter issue.

Malfunctioning Oxygen Sensor

Oxygen sensors monitor the amount of unburned oxygen in the exhaust system. Oxygen sensor problems can lead to catalytic converter trouble, as well as decreasing fuel-efficiency.

Faulty Mass Air Flow Sensor

Mass air flow sensors monitor how much air is coming in and determine the amount of fuel that should be injected with it. When this sensor is failing, the engine might stall out soon after you fire it up.

Bad Spark Plugs

As spark plugs get old and dirty, they're liable to repeatedly misfire, which can reduce performance and gas mileage. For vehicles manufactured after 2000, plugs usually don't need to be replaced for 100,000 miles, while older vehicles tend to need new plugs more often.

Loose/Missing Gas Cap

A tightly sealed gas cap prevents fuel from evaporating before your car gets the chance to run on it. Though it might seem bizarre, in some cases a poorly fitting gas cap is the reason the check engine light is on.

Failing Ignition Coil

To successfully create the spark your engine needs to get started up, you need healthy ignition coils. Signs of an ignition coil problem include misfiring and loss of power.

Problems with Battery/Charging System

A failing battery can cause low voltage at the computer, which is an issue that may trigger the check engine light.

If you need check engine light diagnostics, be sure to visit a reputable mechanic. For check engine light diagnostics & repair in Sterling, Herndon, and Reston, VA, contact the experts at Absolut Autoworks at (703) 437-1607. Feel free to give Absolut Autoworks a call today to schedule an appointment for any of your vehicle's repair or maintenance needs!


Absolut Autoworks Blog
Posted: January 29, 2021

Written and Published By MORBiZ