I have a F22A, it had a burned #1 exhaust valve when I got it, I had a valve job done at a machine shop, put it back together with correct valve lash and drove 10,000 miles. I was driving on the highway yesterday and lost power, now #1 is dead again. I'm not so sure the valve job was the best in the world because I was burning 1 qt / 500 miles. Also, I was never able to get the ECU to run in closed loop, because of some electrical issue in the O2 circuit. Anyway, the motor ran very smooth with good power and no missing at all, and got about 28 miles to the gallon. Can anyone tell me where I screwed up? All I can think of is that the oil burning and/or rich mixture did it.