fixed

 

Well untill you get the o2 sim there isn't anything you can do then? You already answered your own question.

 

but I'd still like to know what else could be causing it (other than my burnt o2 wire theory)

 

Is it tightened in properly? Did you snip one or two of the four O2 wires by mistake when reinstalling the exhaust causing them to short circuit? If you still have the stock cat in place you shouldn't be throwing a PO13X code ...

 

The ecu isnt getting the full 5 volt ref. singal that its supposed to get thats why its throwing the code. check the wires and reset the ecu.