Hey i know that this may sound stupid but i can't the thing out. The size is like 20 or 21mm but i don't have one so i am using a 7/8" O2 sensor socket. I have tried pentrating oil, heat and a BFH but nothing will work. My car is running like crap and I need this fixed ASAP.

 

Well I got it out...only took a torch and an exhaust pipe red hot but I got it out!! But my car is still not running like normal. Is it normal for a new sensor to take a while to return to peak efficiency? Or is there something else wrong? The engine just doesn't want to accelerate...if you give it full throttle the engine just holds at like 4500rpm. Is there a fuel problem? I looked at the spark plugs and the gap is correct and everything appears to be fine. I need some help!!!