Alright everyone I have a buddy of mine who owns a 1996 SVT Cobra with about 130k on the motor. Here's the scenario. Our mustang club met up one night. We drove around a good 50 miles and his car ran excellent. We all went to shoot pool one night and he went out to start his car so we can leave and it wouldn't start. He came over to get me to tell me his car would start. Well when we went back over there he started his car but it took acouple seconds then the car started. It ran really rough by the way it sounded. So we all stop at a gas station down the street to fuel up. When we looked at his car white smoke came just billowing out of the pipes. Popped the hood check for whole in the intake nothing. There is no visbile fluid anywhere. Well sense then the car sat for about a week. My buddy took it to his school (UTI) and hooked it up to every machine you can think of and the only thing that came back was his was mis-fireing on cylinder 5 and running lean on bank 1. So we took all the plugs out and checked them. Some of the plug electrods were bent and has serious oxidation on them. These plugs had less the 100 miles on them. So we put new plugs in it. Now he has a flowmaster cat back with stock h pipe and stock headers. He car used to sound way louder then what it sounded like tonight. Sounds as if something is blocking it or some sort of level is off. The car doesn't smoke anymore at all maybe alittle puff here and there once in awhile but nothing serious like that night. My question is if he didn't have correct compression who wouldn't be getting enough oil pressure correct? Im trying to narrow this down. Since the car had trouble starting at the pool hall and then started smoking could it have sent a bad signal to an O2 Sensor? I mean his car seriously till this day gets on it hard and throws you back in our seat. Bad compression would allow you to do this? I was thinking about putting a new smog pump his is car since his doesn't work and some new 02 sensors to see if thats the problem of why it sounds so much more mellower. We smogged it and it pass super clean all the carbon levels were great. I just don't know maybe you guys ran into a similar situation? Sorry for the long story its just im very detailed. Any help would be awesome thanks guys.