fi4t0mcat

Ok so i have a 2001 m6 ss and the car would make a popping sound under hard acceleration, then is started to idle rough and had almost no power so i checked the code and its the PO301 but the SES doesnt stay on it comes on when it misfires, then turnes off after the car begines to act normal again. What the hell could cause this? its so hard to find because it doenst do it all the time.

mnypitZ

iTrader: (19)

Might be a loose spark plug wire, or check all your electrical connectors to your coils. Could be a coil breaking down sometimes. Also check your grounds. Cracked spark plug? Have you had any work done on it recently? There are a lot of possibilities. If it only starts up and does it on or after hard acceleration, I would look for something loose that could be dislodging under accell then plugging in enough to get eventually back to normal when you slow down.

fi4t0mcat

well yeah i just put on slp headers, borla exhaust, slp cold air intake, slp lid, PP MAF, PP TB, and the TB bypass mod. i checked the wires and the coil and they look good, im about to pull the plug and check it.

mnypitZ

iTrader: (19)

Did you leave the plugs in when you did the headers? If so i bet you broke a plug ceramic. Been there done that. I had new plugs anyway, so it didnt matter, but if you cracked one it may be causing your problem. Also check all around the headers for electrical wires to make sure none are touching, or could touch under hard accell. Spark plug wires too for that matter. Check it in the dark to see if you have any arcing from the spark plug wires.

Also, check the back of the heads for the ground wires. I had a buddy that had them loosen up causing all sorts of problems similar to what you describe. I would focus my attention around the headers though, the rest probably wouldnt cause any problems from the install. Unless you didnt plug something in correctly when you did the MAF or bypass.

Good luck, hope this has helped
John

fi4t0mcat

Yeah that gives me a lot of places to check thanks alot, and yeah i did leave the plugs in when i put the headers on and come to think of it the headers kept getting caught up on the number 1 plug. So would a cracked plug just cause it to miss sometimes?