Just purchased 2004 Wrangler with CEL


Sep 5, 2023
Mineral Virginia USA
I just purchased a 2004 Wrangler 4.0 6 cyl with 88,000 miles. It right off the bat tripped the CEL light with bank 2 sensor 2 fail. The prior owner had a new sensor (Mopar) in the glove box. I checked to ensure it was the correct part number, then installed it. The engine idle seemed to improve. I cleared the code.
The next day I drive it and after several short errands I am sitting at a red light and the CEL comes on. This time its code P0432 bank 2.
I ordered a set of NGK spark plugs for it, that I will change out Friday night. Are the Mopar OEM oxygen sensors any good? Should I try changing that bank 2 sensor 2 to a NTK sensor? Asking because Mopar is new to me, the Jeep has been sitting for a while in a garage, and it slowly seems to be getting a better idle as I drive it, but I have only put on about 200 miles so far. Open for suggestions! Or should I wait to see what effect the plugs have?
Verify that the bolts that hold the cats to the manifold flange are tight.

Update: I checked the exhaust system and the bolts are tight at the manifold for the mini cats.
I have been driving it daily, and the more I run it the better it seems to run and idle (it had been sitting for at least a year since I bought it)
So this morning it was cold out and I drove it into work. I got in heavy traffic and glanced down for a moment anf the CEL went out on its own. I am hoping it will stay that way…
While rolling around under the Jeep my forward exhaust looks like it is in pretty good shape, The rear muffler is in bad shape, not leaking yet, but won’t be long. For now I am just glad the light went out and hoping it stays that way. Wish me luck!
Bigfoot-NM. You are so very correct. I finally had a chance today to get under the jeep and really check the mini cats. From above they appeared tight, they looked tight from below as well, but when I put a socket on the bolts I saw thar the rear cat was loose.
Now I have another problem... since this Jeep had been sitting for a while the bolts are corroded in the manifold nuts clips. I am going to soak it down for several days with Kroil and hopefully I can tighten up the cats without destroying the nut clips.
another supporter for NTK O2 sensors here.
Sounds like you are on the right track.

For the exhaust bolt issue, have you asked a shop what they would charge?
I find that paying for someone else to do the 'shit-jobs' makes me appreciate when I can save myself money on easy shit like the sensor.
Removing stripped-out exhaust hardware is what a muffler shop does all day, every day. They have they tools to replace what's bad while standing on their feet whereas I'd have to do this lying on the ground under the car without the benefit of a torch-wrench if things are really buggered up.