I have a 94' 4runner and would like to change what looks like the factory o2 sensor. Well being I live in Ohio unfortunately it is rust city up here. Well I got a clean runner but the exhaust looks like crap. My o2 sensor is on there and impossible to get off with 6-point deepwells. So I bought some Irwin Bolt-Grips that cut into the bolt to remove them. That didn't work either. Also this has been soaked in PB-blaster. Im thinking now to cut the bolt off and clean the threds vis die. I was wondering if anyone knows of any other way? Thanks in advanced for the help

 

Are they bolts or studs? On mine they are studs. My studs twisted out, so I welded them in place, and used a torch to get the nuts off. If you are replacing the O2 anyway, unplug it and torch the nuts/bolts til it is red hot. Then unscrew them like they were put on last night.

 

http://free-auto-repair-advice.blogs...en-sensor.html

 

Does his 4runner have that style or is it the 2 stud style, like mine?