burritobrother

Hello My '87 DL wagon was real soggy on the gas pedal, I took it to a mechanic who said the cat was clogged. He quoted me over five hundred bucks saying he'd have to "really look" to find one. The first junk yard I called said they had em for fifty bucks. Is replacing the catalytic converter or "Y-pipe" as easy as it looks??? is there any reason I shouldn't try to save myself half a grand some afternoon this next week? will my new-used cat be clogged too? another post on this site suggested pouring some injector cleaner down the pvc (tube?) but Im not sure what that is? I'm no great mechanic, but brave enough to tackle most R n' R (remove and replace) jobs. is this one within my reach? any advise will be apprecited! sincerely burr....