anybody explain this??? all the other plugs were clean but this one wasnt

 

did you have any drivablty concerns ?

 

well at idle sometimes when i start the car up it would misfire really bad shaking the whole engine and the exhaust would be popping like crazy

 

Looks like the plug inst sealing right , or was slightly loose. It's weird to see carbon all the way up the threads. Has it ever had a helicoil or been overtightened? Is the porcelain part loose or wiggle at all? could just be a damaged or bad plug.

 

i also noticed that when i changed the plugs that the dealer put a stock acdelco plug in cyl 2 when they changed the coil..so now it drives better