I have a '95 Pathfinder - has been running rich, then last week, during the drive home from Seattle, kept cutting out, dying, and running like on 4 cylinders (if that) - got on here to this forum & figured that it would be a good thing to replace the o2 sensor -- and also checked with Autozone diagnostics (they came up with the same idea) -- thcar also has over 292,000 miles on it. My boyfriend (not a mechanic- a musician) is trying to get the old sensor out -- but it seems to be heat welded on - the one located by the cat (btw it is a 4-wheel drive auto) PLEASE -- i need help -- we are stuck here with no wheels without our Pathy working -- .. . . . what kind of tools can we use to get that dang old sensor out . . . used a lot of liquid wrench so far . . . and I am hearing a lot of banging from the wrench . . . . . ..HELP!!!! (Please)