Why is my Check Engine Light On?

The last thing you want to see when you get in your car to go to work in the morning (or ever!) is the check engine light. You're driving down the street, totally focused on the 3000 other things you're juggling, then your check engine light flickers on- talk about great timing!

Although getting under the hood is probably the last thing you want to do, it's important to deal with the issue ASAP. Leaving it as a "tomorrow problem" is a bad idea and can put you and your passengers in harm's way.

It's always good to come into a service centre to get the problem looked at by a professional, but here are the most common causes of a check engine light.

Malfunctioning oxygen sensor
Your oxygen sensor measures the amount of unburned oxygen in your vehicle's exhaust system. Over time the sensor gets covered in oil ash, reducing its ability to change the oxygen and fuel mix. A faulty sensor not only reduces gas mileage but also increases emissions. Leaving a faulty oxygen sensor can lead to more serious problems, like a busted catalytic converter, so it's important to get it checked out right away.

Faulty gas cap
The pressure within your gas tank is thrown off whenever your gas cap is cracked, off, or not secured properly. This issue isn't life-threatening, just annoying. But like the oxygen sensor, an unsecured or damaged gas cap can wreak havoc on gas mileage and increase emissions.

If your car isn't driving differently once the check engine light comes on, pull over and look at the gas cap. Make sure it's not cracked, give it a good twist, and see if the engine light turns off once you start driving. If not, keep driving until you make it to a service centre where they'll be able to give your car the one-two and make sure it's not something more serious. And if it does turn out to be a gas cap issue, they can give you a shiny new one.

Defective catalytic converter
Your catalytic converter helps reduce exhaust gases by converting harmful carbon monoxide into carbon dioxide. If the check engine light is a symptom of a malfunctioning catalytic converter, you'll also notice lower gas mileage and poor acceleration.Your catalytic converter shouldn't break if you're keeping up with regular maintenance, but we get it, life happens and keeping on top of car maintenance isn't always a priority. A faulty catalytic converter is usually a symptom of another issue like failing spark plugs or a broken oxygen sensor. If the part fails altogether your car will eventually stop running, running your gas mileage into the ground in the meantime.

Failing spark plugs and wires
The spark plug seals the combustion chamber and ignites the air/fuel mixture inside the chamber. When the plugs fail, they misfire; you'll feel a jolt in your car's acceleration whenever this happens.You should get your plugs replaced every 161,000 km, but it's normal for them to degrade over time. Once they fail, get it fixed right away. It's not super dangerous to drive with faulty spark plugs and wires, but your car will run better once they're replaced.

Damaged mass airflow sensor
The mass airflow sensor measures the amount of air entering the engine to determine how much fuel is needed to run your engine efficiently. Most fail because of an improperly installed, or never replaced, air filter. You should replace the air filter as part of your regular maintenance at least once a year to help prevent the airflow sensor from failing. Driving around with a damaged mass airflow sensor isn't super dangerous, although you will notice a decrease in gas mileage and an increase in the number of times your car stalls. Like the other issues in this list, it's best to go to a service technician to make sure a check engine light isn't a symptom of something more serious.

There are a plethora of other reasons why your check engine light is on, but these are some of the top offenders.

Regardless of why your check engine light is on, it's important to always take it seriously. It can be tempting to play mechanic and try to fix the issue yourself, but it's better to leave this one to the professionals. At Capital Ford Lincoln we have a dedicated parts and service department that goes above and beyond to fix any issues you have with your vehicle. If you find yourself needing your vehicle serviced, give us a call at 204-772-4211 and we'll have you back on the road in no time.