Two Of The Most Common Reasons Your Car's Check Engine Light Came On

For many vehicle owners, nothing is more disheartening than looking at their dash and noticing the check engine light is on. According to Car Care, when a check engine light comes on, this is a sign there is something is wrong in the emission, ignition or fuel injection systems. However, before you freak out and assume your car is headed for the junk yard, it is important to realize that a check engine light doesn't always spell disaster. Here are two of the most common reasons why your vehicle's check engine light is on:

1. A Loose or Damaged Gas Cap

One of the most common, inexpensive, and easy-to-remedy reasons why your check engine light came on is simply because your gas cap wasn't screwed on tight enough or is damaged. When your car's fuel cap is damaged or loose, it impacts the pressure within the fuel system, which causes the check engine light to turn on.

In addition, a loose or damaged gas cap lowers your vehicle's fuel efficiency while increasing its emissions, which is not good for your finances or the environment.

How to Fix

If your check engine light comes on, wait until it is safe to pull over, turn off the car, and check the gas cap. If it is loose or not screwed on the right way, correct the issue before turning on the car. If the gas cap is damaged, head to the nearest auto parts store and purchase a new one immediately.

Continue to drive a few more miles after you tighten or replace the gas cap. If the check engine doesn't turn off, head to your mechanic to ensure there isn't something more serious that requires attention.

2. A Faulty Oxygen Sensor

A broken oxygen sensor is another common reason why a vehicle's check engine light comes on. The oxygen sensor is found on your vehicle's exhaust manifold and its purpose is to detect the amount of unburned oxygen in the exhaust.

The vehicle uses this information to determine the how much oxygen to mix with the fuel. Depending on the type of vehicle you have, there will be either two or four oxygen sensors, and if one or more is faulty, it will cause your engine light to come on.

In addition to causing your engine light to come on, a faulty oxygen sensor can also drastically decrease your vehicle's fuel economy, and, if left untreated, it can lead to a damaged catalytic converter. The catalytic converter is piece of your exhaust system that helps convert carbon monoxide to carbon dioxide, which is great for the environment.

How to Fix

If the engine light is on and you've already determined the gas cap is screwed on properly and tightly and isn't broken, checking the vehicle's oxygen sensors is the next step you should take.

For amateur auto mechanics, it is possible to check for a faulty oxygen sensor yourself. A vehicle diagnostic code reader is a tool that can be purchased at an auto parts store. To use this device, first turn your engine off and plug the code reader into link connector, which is typically found on the dash. Next, turn the car back on and look for a code on the reader's display.

When the check engine light turns on, a code is found in the computer's memory. The code reader recognizes this code and places it onto a screen on the device. The exact meaning of this code can be found on the website for the code reader or included instructional booklet.

If you're not comfortable using a diagnostic code reader, contact a skilled mechanic instead. It is vital to get your car to a mechanic immediately because, once again, a faulty oxygen sensor can lead to more expensive problems down the road.

From simply checking to see if your gas cap is tight to utilizing a simple diagnostic tool, there are many ways to discover why your check engine light came on. If you've exhausted both these simple solutions and the engine light is still on, contact an automotive mechanic through a website like

About Me

Staying Warm This Winter

Ten years ago, I married my wonderful husband in a beautiful church ceremony. Since my wedding day, I’ve learned how much my spouse loves automobiles. He especially cherishes his nearly 20-year-old truck. Unfortunately, he can’t drive this beloved automobile right now because the heater in it is broken. Due to the cold temperatures outdoors, he would freeze if he decided to drive his truck anywhere. He's working now to get the problem fixed before winter is over. On this blog, I hope you will discover the most common solutions for broken heaters in vehicles. Enjoy!