aight look, i had that code forever, mine was not the sensor at all. when you unplugged it to do the exhaust or if you didnt change midpipe, is the wire and connector loose? like the wire and connection are loose, like swinging. I used some muffler wire and tied it so it couldnt move, 1000 miles or so and no more codes. took me forever to find that lol, kicked myself in the but for replacing those sensors...