I did both of mine (upstream of the exhaust) a couple month ago. lost a lot of skin... I took the big cross member out and lowered it with a jack. That allowed me to get at the electrical connector (still difficult and painful but better). there was a plastic tab that held the wire in place against the frame. I was able to remove it which gave me more wiggle room. Couldn't get it back but I think that was fine. I got it all back together and still had the code