O2 sensor trouble codes

So I have a 2013 Jeep Wrangler with a 3.6l eng. It came into my shop after the customer already had a few repairs done at another shop. His engine light came on for an idle air temp sensor, and they changed his iat. Then it came on again, this time for o2 senor codes and closed loop not achieved on both banks. Codes list: p0132 o2 b1s1 circuit high, p0138 o2 b1s2 circuit high, po152 o2 b2s1 circuit high, p0158 02 b2s2 circuit high, p1128 closed loop not achieved bank 1 upstream and a p1129 closed loop not achieved bank 2 upstream... The shop it was at then decided to replace the map sensor and both up stream o2 sensors. Customer left and the light came on again for all the codes I just listed, customer took it back to that shop and they told him it’s stuck in open loop and they can’t get it to duplicate his concern. So, now it’s at my shop. Customer complaint is it drives fine but after a while of running it runs really rough almost has to give it gas to keep it running.. That’s as much history on this jeep I have and very little detail. It came in late so I haven’t had a chance to look at it. My first thoughts are what o2 sensors were used as Chrysler uses a ground bias and after market o2 sensors are no good, however I have a feeling even replacing them with NTK sensors I may still have a problem? Any experience and tips with this sort of issue, is it common? Any suggestions as to how to approach this would be great, thanks in advance..

First thing I would do is start with the vehicle completely cold, set up your scan tool to monitor all 4 oxygen sensors(and maybe O2 sensor heater current PIDs if available), the 4 fuel trim PIDs, the MAP, IAT, ECT and BARO PIDs before you first start it. Verify that the oxygen sensors all show the bias voltage reading on scan tool, and ensure that the MAP and the BARO sensor pressures match, and the same thing with the ECT and IAT PIDs(within 3 to 5 degrees of each other), then monitor the data immediately after starting it, let it idle, no throttle input, and watch for the upstreams to drop off that bias very quickly, and for the downstreams to follow soon after the upstreams, and for the MAP sensor to be around 10-12 inHG once the idle speed stabilizes at normal idle speed. If the bias is not there or the sensors don't drop that voltage quickly, then there might be a heater or signal wiring fault, or PCM issue, or the aftermarket upstreams might be a built in problem from the other shop and may possibly need to swap for OEM genuine sensors. If they didn't replace the downstreams then I would look away from possible sensor issues and more towards an engine running condition causing the sensors to stay fixed rich. If they stay fixed rich and it won't go in to closed loop, then run engine at 2,500 in park for 3 minutes to get the sensors nice and hot, then see if they show activity. If they stay rich, then introduce a large vacuum leak to see if the sensors respond to the lean condition. If they do, then you have an actual rich condition occurring that is affecting the whole engine and causing the signal voltages to stay high. If that is the case, verify that the EVAP purge valve is not stuck open allowing excess fuel vapors to get into the mix. If they still stay fixed rich, then wiring checks are going to be necessary, and we can discuss that possibility after the preliminary checks I listed. With the fact that the upstreams were replaced and the customer took it and the light didn't come back on immediately but did as they drove, as well as the roughness after a while of driving it, I would put actual circuit faults low on the list of options, since real circuit faults should set immediate fault codes. If you bring the results of those checks back here, I'd be more than happy to try to work through it with you from that point. Hopefully that gives you some decent paths to follow to start narrowing the possibilities down. Good luck testing.

--T.J.

Thanks so much, that’s a huge help, I had a list of things I wanted to check and you got them all I just wasn’t sure if the order. I’ll keep you posted, thanks again

Definitely, more than happy to assist. Look forward to hearing back from you.

--T.J.

This started with an IAT problem that turned into parts throwing contest.

My starting point would be the code that indicated the IAT problem to start with. What was the code? If a ground wire was compromised and that ground wire is common with the 02's that would set off the codes on the 02's which led to the next mistake, using non OEM 02 sensors on a Chrysler product. Those original 02's are probably Ok but gone now...

A good history from the owner as to how issues occurred would prove invaluable.