What Is My Car Trying to Tell Me? The 5 Most Common Causes of a Check Engine Light

The check engine light is the most frustrating of all the dummy lights on your console. It's passive aggressive, telling you yes, there is a problem, now figure out what. Some may ignore it and wait for other symptoms to surface that will direct them to the problem. That's not good. You could potentially be allowing a small problem manifest into a big one. But you also don't want to spend half a day at the mechanic just to find out the problem is something you could have fixed in your driveway.

The easiest and cheapest solution is to make a quick trip to your local auto parts store. Most are equipped with a diagnostic tool that reads the codes from the check engine light. This is usually a free service they provide in hopes that you will purchase your parts with them. Which you should.

A dirty oxygen sensor is a common culprit for the engine check light annoyance. This part is measuring the amount of unburned oxygen that is left over in the exhaust. If it isn't working right you are losing gas and increasing emissions. Not replacing it could cost you the price of a new catalytic converter, so buy the new O2 sensor and replace it right away. This is an easy job to do if you follow the owner's manual instructions.

Believe it or not, your gas cap could cause the check engine to come on. This is one of those things that you can check before you get to the auto part store. If after tightening it the light goes out then you have effectively found and solved the problem without embarrassing yourself. If you do make it there and the diagnostic tool still points to the gas cap, it could be faulty or cracked. All you need to do to stop gas vapors from escaping and turn off that dumb light is replace it with a new one.

The most expensive and problematic cause of the check engine light is a faulty cataltyic converter. This is a big problem that needs to be addressed immediately by a mechanic. There is no easy fix here. If the cat converter has gone bad you have no other choice but to replace it.

Another sensor that can make the check engine light start crying is the mass airflow sensor. This one is like the O2 sensor, if its busted emissions are increased and gas mileage is decreased. Unlike the oxygen sensor, you can't replace this one yourself. You can however increase its life span if you would just change out the air filter like you are supposed to.

Lastly we have the spark plugs. If one stops working it will trigger the check engine light. Luckily for you the auto parts store will most likely have them in stock and if you know what you are doing you can just go ahead and replace them at home.