I had a mechanic look at my car the other day and he said I had an exhaust leak. I have felt all around for a leak but can't find anything. I checked all the nuts and bolts on the headers and they are tight. I did tighten the clamps on the crossover, but it was only a small amount, shouldn't have been enough to cause a leak. I saw the mechanic again today, and he said he hoped it wasn't a valve issue.
I just switched to E85, and I'm wondering if that could cause a sound like an exhaust leak. I don't see how it would, but I'm not a genius.
