As most of you know, tracking down wiring issues can be a PITA. I bought my son a 2002 Mustang GT with some mods to include LT headers, a hi flow catted SLP exhaust and some other goodies. The problem is that the damn rear O2s and heater circuits had many codes. Replacing them didn’t fix it nor did eliminators. Eliminators still require working O2s. So I knew the problem lay in the wiring. Neither the installer nor a separate shop was able to fix the problem. They kept blaming the long tubes or the hi flows. Wouldn’t even listen to reason when I explained why this wouldn’t be the case. Finally, I traced the wiring harness and found the O2 harness wires were crunched under what looks like the trans mount. Upon inspection I saw tons of copper peeking out. 6 of the 8 wires were cut. Once I fixed the wires the problem was gone and after some driving was able to pass inspection. Thank god and thanks to some of the other members who posted solid info on how to check the wiring on these pigs- Clampett5 out