[mustang_montana]

so i threw my old midpipe on last weekend and the stangs run like shit since. its a catted midpipe with magnaflow high flows, but i had it sitting out behind my shed all winter. the cats heat up real quick and real hot, and i can here them hissing real bad when i turn the car off. car ran great befor i put that midpipe on, rear o2s are disabled and front ones are new and fine. no leaks anywhere, nothing else was done just that midpipe. so would shot cats heating up real bad mess with the front o2s due to the heat? thats when the car runs like shit is when it heats up. runs good cold. when i say runs like crap i mean it runs like its leaning out, giving it gas it will stutter and act likes its gonna stall out.