This may be well known on this board, or have been discussed previously, but I wanted to pass along my experience.

I had a CEL come on. The dealer said it indicated that my Mass Air Flow (MAF) sensor had gone bad and needed to be replaced ($400 P&L). I looked into it a bit and found folks on other car forums that said you could clean it with brake cleaner.

I actually found a can of MAF cleaner at Pep Boys. Removed the MAF using a Torx security bit, sprayed it several times until it was shiny and bright, and put it back. Reset the CEL and now, after about 10,000 miles (knock on wood) no recurrence of the CEL.

I hope this saves someone else some $$$!