2006 1500 slt with the 4.7l. I've owned the truck for close to a year, and it's been pretty solid. It was throwing a code for the o2 sensor every once in a while, so I recently replaced all four sensors. Since doing that, I've been getting the p1128 and p1129 codes, no closed loop fueling. I've cleared them and reset the computer multiple times, and they keep coming back. My fuel mileage has increased from low 15s to almost 16, so I believe it is going into closed loop. It's also developed an issue where it will stumble and sometimes stall once it's warmed up, but I'm not sure if these two are related in any way. Has anyone else had this happen? Any ideas what it could be? Did I get two faulty sensors?

 

Verify you have the sensors plugged in to the proper connectors. Front sensors you should see the voltage bouncing between 0 and 1 volt, rear sensors should be pretty steady. If that is correct, check fuel pressure. See what that looks like.

What brand sensors did you install? If they are bosch sensors, that is at least part of the problem.

 

They are Bosch sensors. I've ran those in everything else I've driven and never had an issue, so I assumed they would be fine. What would be a good brand to use, other than the Mopar ones?

 

Denso or NTK are OEM suppliers.