I went out and bought a new set of header gaskets. I was told that byson gaskets were the best and they were fairly inexpensive and so far they seem to be holding up good so far. But after I installed them there was a severe loss in power and now my car backfires under acceleration sometimes. I checked the plugs and # 2,4 and 7 are white but #1,3,and 5 are black and sooty and #6 and 8 are wet and smell like fuel. I already checked the connections and they are all tight and there are no engine codes popping up. Do you think it has something to do with the new gaskets or something bigger? The car ran fine before and the only problem I had was the header bolts loosening up.

 

it seems like one injector is over fueling. could you have crossed a spark plug wire?

 

Yes i found that this morning. I had crossed the # 6 and 8 wires. Thank you