start with replacing the upstream o2 on bank 1, which is the right side (passenger side ) bank

and ive seen 02 sensors go bad at far less miles, dealer should good will an o2 sensor if you are just out of 3/ 36k

 

I think that is where I will start tomorrow. I just priced them at Autozone and I can get the up and down stream Bosch sensors for $50 with a $10 mail in rebate. That isn't bad at all. Heck it costs me $15 just to drive the Jeep to the dealer so $40 or so to replace both sensors isn't bad. Hope this clears up the problem as I leave on vacation next Friday and I planned to take the Jeep.

 

the p1128 code is a result of the o2 sensor code

 

Yea I kinda figured that. I just thought it was odd that the O2 sensor went out already. I might replace both the upstreams instead of the up and down on the Passenger side.

 

i would just replace the 1 upstream on the one side

 

I replaced both upstreams and it seems to have fixed the problem. I had autozone cash and there is a rebate if you buy 2 at the same time. Basically paid for one and the other was free. Figured why not replace them both. I'm going on a long trip starting Friday so I'd rather be safe. It seems to also run much better so I'm happy.

 

I am getting the same two codes on my '15 Sport. I am going to try replacing the bank 1 upstream sensor, but I wonder if there might be a different cause.

When the CEL first came on, the Jeep would intermittently have low acceleration/hesitation problems. When I tried to accelerate, it just wouldn't pick up and the engine was struggling. The mechanic found a seized caliper and wanted to fix that first. He also found a leaking oil cooler, but I put that off for now. After that, the CEL came back (same codes) but it drove fine for a few weeks with the CEL on. Just last week I started getting slow acceleration on every cold start. I can fix this by pulling over right away, shutting off and restarting the Jeep. It drives fine after that, even though the engine has not really warmed up yet. What can be causing that?

 

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