I have a 99 Civic EX and i'm trying to remove the catalytic converter in order to remove 3 bolts which are rusted solid to the flange. I removed the bolts holding the cat in no no problem, but the O2 sensor will not move for anything. I greased it up with some PB Blaster and having been twisting my heart out trying to move it, but it won't budge. Someone please help!

 

well grease the hell of it and use that 02 sensor removal tool and a breaker bar to get some leverage. mine was like wow too just put some muscle into man good luck

 

Take the cat off, cut the 02 sensor wire, put the cat in a vice. Get a socket wrench. Buy a big ol steel pipe. Slide that over the socket wrench, 4 feet of leverage will get that sumbitch off.