Check engine light

The check engine light has been going on and off for a couple of months. I took it in to be looked at and the mechanic said they couldn’t get a code, couldn’t get a “good read” on what was wrong. They said I could take the car back (but they couldn’t give me an inspection sticker) and drive it for a couple of days and if the light comes on, take it back to them. If the light doesn’t come on after a few days, they will give me the sticker. I can’t believe my car is going to act any differently than it has for the last few months – light comes on sometimes, sometimes it doesn’t. Shouldn’t the mechanic be able to tell what’s wrong?

No the mechanic might not be able to tell what is wrong.

The next time the light comes on drive it into any big-chain type auto parts store and ask them to pull your error codes. (Most won’t do it unless the light is actually on at that time). Write down the exact codes. They look like “P1234” and either post them here or take them to your mechanic or both.

There are also plenty of scanners that will read “history” codes. Anytime the light has been on but has turned off there should be a history code stored. Not all code readers will pick them up. If your mechanic is guilty of anything, its probably not having a very good scanner.

Also be kind enough to give us the make and model of the car, the year, and the mileage. Some cars do have characteristics and that information might allow us to help you better.

I talked with the mechanic again today (this is at Sulllivan Tire – I don’t have a relationship with any other mechanic), and he said all they could get was a generic emissions code, which told them nothing. And then he went on and on about about six different categories which had to be reset and they could only get five to reset, so I’m to drive the car around for a couple of days, which should get the final category to reset and then take it back to them. If the light comes on again, they’ll start the diagnoses again. If the light does not come on again, they’ll give me my inspection sticker (which is why I went in in the first place). Who’s on First.

Thank you for your help. I have a 2005 Scion with about 60,000 miles.