Just replaced the pass rear o2 sensor because of a p0138 and p0158. Light came back on this am. It's a high voltage code so I am guessing that it can't be a cat since the sensor should only read 0-1v so what ECM? Anyone else expirance this problem. Oh. I used a factory o2 sensor as well because I true an aftermarket and didn't think the truck liked it.

 

P0138 is bank 1 sensor 2, drivers side after cat. P0158 is bank 2 sensor 2, passenger side after cat. If you just replaced the passenger side then you're only half done.

 

Im in almost the same boat. My pre 02 sensors went out so i replaced them then the rear 02 sensors threw a code.

 

Firefighter, I think that's common. The rears are probably lazy.

Mine is showing rear o2 sensor voltage high. It was a 0158. I changed the o2 now I have the p0158, p0138. I am wondering if the problem lies in the upstream sensors. They seem ok when monitoring them, but then again the catalyst has passed now. The mil trip was 60 miles ago. So it's intermitant. Anyone?