Stripped 02 nut..suggestions?

[DaRkCotTon]

Alright, so yesterday i bought a o2 sensor socket and some wd40 from autozone and prepared to get the 02 sensor off. (it was rusted and i had a CEL). So i spray some WD40 on that thing and waited, sprayed some more and waited, then sprayed it again and waited. after i was done playing a GTAIV mission, i went outside and put the o2 socket on and started ratcheting the thing loose. unfortunately, all i ended up doing after 2 mins of work was stripping the effing nut. now its basically rounded off and im not too sure on what to do. a friend of mine told me to blow torch it and then try again, but im not too sure about that. should i bring it to a garage, or is there a tool i can use to take it off? any type of suggestion would help. Thanks in advance

P.S. its the pre-cat 02 sensor i stripped, dont know if that would help.
P.P.S Wasn't sure where to post this

[xxxmonoxidechil]

if you allready stripped it, then a torch isnt gonna help. if your tried it 1st, you probably would have been able to remove it though. heat works better then any penetrating oil...

[_Slotegé_]

You can try to heat it up, then put a vise-grip on it really tight and tap the vise-grip with a hammer.....

[MakeMeGoFast]

Try a pipe wrench

[DaRkCotTon]

Thanks everyone..already tried the pipe wrench but the one i had was too big..has anyone heard of the "Metrinch" wrench? I found it online and it said that it can loosen stripped nuts and stuff.