Check Engine Light Issues: An Overview

13 July 2021
 Categories: , Blog


Few things can cause a car owner to panic quite like the appearance of the check engine light on their car's dashboard. For most, the panic is a direct result of the fact that the light isn't a clear indication of the problem, unlike the oil light, transmission light, and other similar warning indicators. The check engine light is a broad indicator that there's something amiss in the engine or the emissions system. Here's a look at a few of the most common reasons for the check engine light to come on.

Loose Fuel Cap

Perhaps the simplest check engine light issue to resolve is a loose fuel cap. Because your engine's fuel system relies on a specific vacuum and pressure level, it is dependent on your fuel cap being properly secured. 

If you stop to fuel up and you don't get the fuel cap tightened fully, the system won't be able to create the necessary vacuum for optimal operation. As a result, a sensor will trigger your check engine light.

Any time your car's check engine light comes on, the first thing that you should check is that fuel cap. Make sure that it is tight to rule it out as the cause.


Whether it's due to a fouled plug from a leaking valve cover gasket, a generally faulty spark plug, or any other problem with the combustion system, a misfire in your engine occurs when a cylinder isn't firing the way that it should. This can rob your engine of power and, if left unaddressed, can result in a buildup of unburned fuel in the engine that might spark a fire.

You can have a service center scan your car's computer to determine if the problem is a misfire. If it is, the computer will store a trouble code that indicates which cylinder the misfire is happening in. This makes it easier for you to schedule the repair because you'll know precisely which cylinder is misfiring.

Oxygen Sensor

Your car's oxygen sensors are an essential part of the exhaust system. They read the percentage of oxygen mixed into your car's exhaust. If the oxygen reading falls outside of the programmed parameters, whether due to an emissions problem or just a faulty sensor, you'll have to have it addressed.

Your repair technician can check the engine trouble code to determine which oxygen sensor is tripping the light and then replace it to determine if the problem is in the emissions system or the sensor.

These are three of the most common causes for check engine light issues. If your car's check engine light is on, reach out to a technician who provides car check engine light repair services right away.