Our '06 tC's check engine light keeps coming on not too long after we get the guys from the local oil change place to clear it. The last time the guy said that it's probably the catalytic converter that is causing it to come on. When my wife drives it she isn't getting as much mileage as she once did.

I don't think it's the cat converter though. I had someone else look at it and he says that the temp range between both converters doesn't lead him to think that is the problem. Any ideas?

 

do you have the Cel code or codes ?