O2 sensor wiring short

[Ashkid98]

So my jeep has been down for a while. My pcm was fried so I got a used one and when we got the used one my mechanic coworker found a short with the o2 sensor which is what fried my original pcm. Well it ran great for two weeks and now I’m having issues with the wrangler starving for fuel on acceleration. If I unplug the o2 it stops starving on acceleration but still doesn’t have the normal power it should. Put a new o2 in it and it changed nothing. I decided to get a whole new harness in hoping to eliminate the short all together but the new harness had no power going to my ign coil so it wouldn’t start. I put my old harness back in and it starts again but I’m back to square one. I miss driving my jeep but I feel like I’m in over my head.

 

[hear]

If it was a "new to you" harness it's entirely likely you just traded one problem for another. If I had a harness pulled out of my jeep, I would rip off all the loom & tape & really inspect it, as well as to check for continuity & probably test light each run. Just as a best practice. I don't have anything specific for your issue, but it very easily could be wiring and given where you're at I would probably start there.

 

[macleanflood]

I'd probably also send your "new" PCM to www.wranglerfix.com @Wranglerfix - Mark - inspect and test the PCM.

Do you have the ability to read live ODB data?

What brand O2 sensor?

-Mac

 

[Ashkid98]

It’s been a while since I’ve been on here so I figured I’d give an update. After about 12-1500 dollars in parts and lots of sweat and tears my tj runs like it did when I got it 10 years ago. First thing I did was replaced the fuel pump which has probably the biggest job I’ve ever done on my jeep so I’m very proud of myself on that. That fixed my issue with the wrangler over fueling on idle but starving for fuel when I tried to accelerate. But I then realized one of my wheels was super hot and it still had very little power so I found my front caliper was locked up. Two new calipers and hoses in the front it felt better but not great so I got a new pcm from wrangler fix because that’s where all my problems began because of a fried pcm initially. With the new pcm in my jeep was sooooo much more happy lol. The only problem was it would run through all the gears no problem and had so much more horse power but I now had a rev limiter set just beyond an rpm high enough to get to the next gear. After checking codes I had one for a high voltage MAP sensor which had been replaced within the last 2 years but I said screw it and through another one on and then the rev limiter is gone and my jeep runs like a top. I feel like I’m back in high school again and I’ve driven it everyday to work for the past 2 weeks. I wanna say thank you to all the knowledge people have put to this website it really helped steer me in a good direction because I am certainly no mechanic. But if you love something enough it’s worth the hard work to keep it going!