You’re driving down the road when you notice it – Your check engine light is illuminated on your dashboard, causing a growing worry as you wonder what it could mean. What if it’s something serious? How long do you have before something breaks down? And, oh my God, will it be expensive? It’s this last question that tends to make people panic. So what do they do? They figure they’ll save some time and money, and they head over to the auto parts store for a free “check engine light test.” I’d like to explain why this is such a bad idea, and why you should head over to your licensed mechanic instead.
The check engine light is a warning, letting you know that your car’s computer detects a malfunction in either the engine, fuel system, pollution system or other critical components. There has been a lot of misleading advertising in the past few years, mostly from chain auto parts stores offering free check engine light testing, that leads some people to believe that by simply hooking up a device under your dashboard and reading error messages (provided in codes) an accurate diagnosis can be made. This is simply not true.
When your car is connected to a machine for a check engine light test, error messages offer clues that trained mechanics will interpret, prompting them to do more specific testing that will narrow down the cause of the problem. While chain parts store employees are proficient at what they do, they don’t have the resources, training or proper test equipment to go beyond this very basic first step or to develop a thorough diagnostic strategy that would be performed by a professionally licensed automotive repair facility.
In short, going to a parts store to have your check engine light tested is like going to a drug store when you’re hurt or sick instead of going to the doctor. Simply taking a part store error code to your mechanic and telling him what part to replace could end up costing you in the long run – either by replacing the wrong part or by paying for work you may not need. Yes, there are fees for diagnostic tests run by mechanics but, in the long run, you get a clear picture of what’s needed and only pay for those necessary repairs.
Please don’t be fooled by “free” check engine light testing. Remember, it’s free because it’s the easiest part of the diagnostic process, and part stores use this advertising strategy to get people into their stores. Just as you’d go to a doctor to investigate any nagging health symptoms, taking your car to a licensed mechanic will ensure that your car gets the right care, after a thorough diagnosis is made by a qualified professional.