A loose gas cap could be the reason your check engine light is on

Dear Ask a Mechanic,

My check engine light has been turning on more frequently than it used to. I just visited the mechanic two weeks ago, who said everything was okay, but now my check engine light is on again. Besides the obvious, that there is a problem with my engine, is there another reason that could be causing this? – Looking for guidance

Le said there could be several things that cause this since vehicles have multiple sensors. “It could be something so simple, like a gas cap, or something in the system that is not going to affect (how your car runs),” he said. In the case of a gas cap, for example, because gasoline vapour is a pollutant, the check engine light would light up if the gas cap is loose or not properly closed. The check engine light, also known as a malfunction indicator light, notifies you when there is an issue that is causing your vehicle to produce emissions that are more than what is pre-determined to be normal. As a starting point, Le said you could look at some reputable and trusted online forums about car maintenance to learn what caused similar check light issue for other car owners. It may reveal a number of causes and how they were resolved. It’s also best for drivers to take the opportunity to sit down and talk to their mechanic since the more information they provide about when the problem is occurring (for example, after filling up the tank) might help to diagnose the issue.

Dear Ask a Mechanic,

I’ve been thinking about purchasing a portable tire pump for my car. With so many options on the market, I’m very confused with how to proceed. What should I be looking for in a pump? Would it be better to purchase an air compressor? – Pump purchaser

Andrew Le, co-owner of 1 Four 0 Nine Inc. in Toronto, said it’s a great idea to have a mobile tire inflator in your vehicle in case of emergencies. Driving on a flat can cause damage to the vehicle, and it will likely cost much more to repair those issues than it would to purchase a portable tire pump. He acknowledged the large selection can be overwhelming but added that researching what is available on the market will reveal that many portable tire pumps have similar, easy-to-use features, rely on the vehicle’s power socket for energy and might even feature a tire pressure reading on a gauge or a small display screen.

Compared to the larger, bulkier air compressors (even portable ones) that are available, “a mobile air pump is a lot cheaper,” Le said. He added portable pumps are available at many stores, including Canadian Tire and Costco.

END TAG: Ask a Mechanic is written by Nida Zafar, a reporter at The Pointer who grew up in a house full of mechanics in Scarborough, and occasionally poses your questions to her dad or brother. You can send your questions to wheels@thestar.ca. These answers are for informational purposes only. Please consult a certified mechanic before having any work done to your vehicle.