I was going to get my exhaust put on my 04 cobra. I took it to my local speed shop they were going to install a bassani xpipe, and a borla cat back for me. So I drop off the car and they get to work on it but then the guy gives me a call saying that they can't take the 02 sensors out of the stock h-pipe. He said that there was a chance that they would break if they forced them, and that when he tried to remove them the sensors would bearly move. He told me that I would have to sign a waiver for them to proceed, so I just had them put the cat back on for now. But has this ever happened to anybody, and if so what would you suggest for the removal of the 02 sensors. Then the guy suggested that I buy four new 02 sensors to put on the X-pipe and just leave in the ones on the H pipe incase I ever wanted to swap out again it would be easier. So I don't know if this guy is just trying to con me into buying 02 sensors for $400 or if hes being honest and there is a chance that the sensors could break trying to remove them.