Unexpected Reasons Your Check Engine Light Is On

How This Light Works

Your engine control unit monitors your engine's performance, along with other related components. When this computer collects data that is outside of normal operation, it records a specific fault code that relates to the issue. The Check Engine Light then illuminates to alert the driver that something is wrong. In most cars, a flashing Check Engine Light means something should be done immediately, while a steady light means a minor issue that should be checked soon.

What Your Check Engine Light Means

There are few feelings more intimidating than watching your car’s “check engine” light blink to life. This little light is so confusing simply because there are so many possible reasons it has suddenly decided to make an appearance. Driving around, hoping and praying the light turns off won’t do much good. If your “check engine” light has recently turned on, here are three possible reasons why.

Fuel system Issues

  • Faulty Gas Cap - Your vehicle is pretty good at warning you of any potential trouble. Something as simple as forgetting to replace the gas cap could cause your “check engine” light to come on. This is because the gas cap keeps vapors from escaping the fuel tank. A loose or broken gas cap can dramatically reduce fuel efficiency and increase emissions.
  • MAF Sensor - Mass airflow sensors are a common item to go bad. A MAF sensor sits near the engine and reads how much oxygen is being let into your engine along with gasoline. There is a certain level of oxygen the engine requires to run efficiently and stay safe. When the MAF sensor goes out your car no longer reads these important levels. This is a simple fix that requires only a replacement of that sensor in your vehicle.
  • O2 Sensor - The combustion process requires a very delicate mixture of chemical gasses. The O2 sensor monitors these gases to make sure the right amount of oxygen is present. When the O2 sensor fails, the vehicle cannot perform as needed. This significantly reduces fuel economy and could end up costing thousands in damages. Replacing your O2 sensor at the first sign of trouble will save time and money in preventable repairs.

Exhaust Problems

  • Catalytic Converter - A catalytic converter takes dangerous gases your vehicle produces and makes them less harmful. If your catalytic converter fails, you are putting yourself and the environment in danger of high output of carbon monoxide and other harmful gases.
  • Faulty Ignition - Spark plugs ignite the fuel as it flows through the engine’s cylinders. Spark plugs are a small part of the vehicle and fairly cheap to replace – usually about $10. However, failing to replace a spark plug could lead to catalytic converter failure or other serious problems.

Diagnosing the Check Engine Light

Because the check engine light may be hinting at any number of problems, narrowing down the pool is best done with a diagnostic tool that can help pinpoint the problem. When the diagnostics have been run, a code is sent to you that informs you of any repairs necessary for your vehicle. After we have found out exactly what the problem is, our experts will provide an itemized estimate for you to look over. We’ll never make any service decisions without first asking for your approval.

Whether your check engine light just came or you’ve been looking at it anxiously for thousands of miles, we can help you determine the problem and fix it.

Call Christian Brothers Automotive today to schedule your next service appointment.