2001 o2 sensor issue
 

(Originally posted in 968 area)

I have an 01 model with 36K miles. The CEL came on recently and the codes read P1126, and P1131. My question, is there a way to tell which of the sensors need replacement either pre or post cat.

Thanks

99% chance it IS NOT an o2 issue, that is an adaption/ fuel trim related fault......there is probably a vacuum leak somewhere....bad aos.....etc......
you need to have this diagnosed before throwing parts at it

Approach this thinking something else is causing the reading. Most likely a loose or broken line. The codes for a bad O2 sensor are very specific.

There can be about a half dozen possible causes. Use the search the forum function of this software with a value like P1126 to find threads speaking about this code and there are usually postings where someone has posted a list of the possible causes.