He fixed what the dealer couldn't. I took my porsche to the porsche Dealer off 80 by Sierra college and they said they fixed the stutter my engine had after a $700 bill for changing the spark plugs. Nope it was still there. So I took it to Jim and he found the issue. He showed me how the Dealer didn't even change out all the plugs, even though they charge me for it. I will never go anywhere else.