A few months back I had a shop install a high flow cat for me. They had to weld in 2 o2 sensor bungs as well. Turns out the position which they had the secondary bung made the wires on that sensor chafe off the shift linkage. A few weeks back I got a cel because off this and the car has been bogging like crazy. Now they need to remove the cat and re-weld the bung and a little more of an angle so the wires wont be rubbing the shift linkage and i also need a new sensor. I have to go in tomorrow with it, do you think i should get the repair done for free? Thats what I am hoping considering it was all their fault. They ruined my factory o2 sensor and those things are damn expensive!!

 

I guess they should, it would be good work ethics, but theres no way to know because every shop is different...