Hi, I have a 1999 Jeep Grand Cherokee 4.7 V8 with Federal Emissions (2 o2 sensors), however my jeep is giving of codes for P0152, P0130, P0136 (meaning 4 o2 for California edition), I changed out the pcm assuming this was the problem but this problem still consists it says in the codes the bank1 and bank 2 sensors are reading high etc (codes seen above), could this possibly be caused by bad o2? Why would it be reading 4 o2 on a federal emission shouldn't it only be to, any help would be great thanks!
First, put back the old pcm. Shame you spent the money on the expensive guess.
The system needs to be monitored to see what readings are coming from the o2 sensors. It may not be the sensors. They may not be able to do there job from some other system failing. Thats why you need a diag from a shop as codes never identify bad parts, just failed systems