My check engine light is on, now what?
If I had a dollar for everytime I heard someone ask me, “What causes my check engine light to go on?” I would be living on a beach in Hawaii by now. Check engine light problems are becoming a common occurance. The main reason for this occurance is because todays vehicles are computer controlled and monitored by numerous sensors; which work hard keep the vehicle fuel efficient and safe.
So what does it mean if your check engine light is on?
Well it could be something as simple as a gas cap being loose or something more difficult to diagnose like a loose or shorted wire. Either way if your check engine light is on, it is a good idea to take the vechicle to an automotive repair facility that has the equipment to properly diagnose the problem.
What if the vehicle is running just fine?
It still may be worthwhile to have the problem properly diagnosed. I have seen many vehicles that appear to run just fine, however they become less fuel efficient. Eventually, the cost of fuel could out-weigh the cost of the repair. Also, cities that have emmisions standards may require you to have the vehicle repair at your next inspection.
Doesn’t Autozone scan the vehicle for free?
Yes they do. However, all they will give is a trouble code. These trouble codes can state something like “O2 Sensor Lean” or “Bank 1 Sensor 2 Rich” which means that one of the oxygen sensors is reading rich or lean. This doesn’t mean that the oxygen sensor is necessarily bad. It could mean that the vehicle really is running rich or lean. This could be due to the failure of another sensor, switch, or other mechanical problem. I have seen many do-it-yourselfers without proper diagnostic equipment replace part after part after part and still not fix their problem. Your best bet is to take your vehicle to a reputable shop and let them diagnose the problem. You will probably have to pay for diagnostic time, which can range from a 1/2 hour on up to 4 hours, depending on how difficult the problem is to locate. In most cases after the part has been replaced the trouble code must be cleared with the use of a proper scan tool anyways, so it’s not worth wasting the time and money by being a parts changer.