mustang_montana

car runs great until it heats up then it runs like its running lean, this happened after i put my old catted midpipe back on. o2 sensors are fine, tune is good enough (little rich if anything) and there are no vacuum leaks. car ran 100% before i put this catted midpipe back on, it had been sitting behind my shed all winter wrapped in plastic. im thinking the cats are shot because they heat up like a bitch, and being out all winter could have done them in (had nowhere else to put it). could anyone confirm that shot cats would cause issues, the rear o2s are disabled which is why im skeptical. im almost positive the cats are done though, just want to know if them over heating could be messing with the front o2 sensors. thanks for the input.

Master

you might have to take it off... them mudddiver bees might have that bastard clogged with mud or maybe a birdnest.. i dunno but its a try...did you have that problem when you did use that midpipe???

mustang_montana

it ran fine during fall before i took it off. a bunch of crap shot out the tailpipes when i first fired it up with it back on though. chances are good they are ****ed, but i dont want to drop 150$ for new ones if thats not whats causing the messed up o2 readings.i really dont see how them overheating would effect much, the rear o2s are disabled so they wouldnt pick up anything.

wwmost

yea the **** inside the cat's prob broke down during the winter. and when you fired it up for the first time the stuff inside the cat prob shot out or maybe its clogged cuz all of it didnt come out. iono but you did say you had an o/r h pipe before soo you should put that in and see if the same problem accures. btw why dont you just leave the o/r pipe on? emissions?

mustang_montana

yeah the stuff that shot out was leaves and such, and i dont think its clogged much if at all cause it flows out the tail pipes the same as usual. though i have no idea how cats are setup inside so the baffles or whatever might be toasted. yeah i put it back on for emmisions, nh's awesome new law.