I had my camshaft timing checked by another mechanic, and sure enough, the timing is off. That's what's causing the CEL to light up. Apparently, the other garage didn't time it correctly when they installed the new head gasket. Unfortunately, there's also a bolt in the valve cover gasket that's stripped and needs to get tapped out and the mechanic thinks that the serpentine belt tensioner is going to snap when he removes it to get to the camshaft. What I thought would be a $300 job balloons to a $950 job. All because the previous mechanic didn't do his job. On top of that, I had it there 4 times to look into this CEL and never once did they mention that they should/would check the camshaft timing. Apparently, they didn't want to put their mechanic's time into it. I wish I had some kind of financial recourse with them. I'm now out another $950. Piss me off!!