Chewgoddit, friend

 

Dodgeric, PLEASE tell me that this worked and was the simple solution!!!

 

at the connector, i used a side cutter to cut the plastic peg thats pushed into the anchor point. this allow the wires to swing out where i could squeeze the release tabs. when reinstalling, just use a tie wrap to secure the wire back to the anchor point.

 

Good news!!.
I changed the upstream and I figured I would change the downstream as well. I could not reproduce the problem with sucking air and eventually stalling out. So problem solved almost. The truck was still shaking at idle so I did something that has been on the back of my mind. I cut open the side of the cat and found the honeycomb was split ( broke) in two across ( short length) with the front loose and flopping around. When I gutted it I could tell where at the split the two halves would rub and alot of the passages were crushed closed. I welded it back up and it idles alot better, can hardly notice any shaking. There still is the occasional slight wobble but I can live with that compared to how it was. It may be possible that the cat has been giving me problems and until recently my O2 sensor started failing making the issue progressively worse.
Tips: Use 22mm open end wrench to change the O2 sensors. The sensor socket sucked and wanted to strip the head. The wrench took quite a force but they broke free fairly easy. I did put some penetrant fluid on a few hours ahead. Thanks dhvauhan for the tip on the connector.
Thank you unregistered user for helping me realize why the sensors would have good reading but still be failing. It made sense after your write up.

 

Awesome! I'm glad you got it fixed. Silly little problems like these can make it tough to trust your truck.

You're welcome. Always glad to help.

 

That's awesome Dodgeric! Thanks for sharing your results... I'm off to the parts store this morning!

 

I just bought a 1997 5.9L gas with 250k miles, having the same problem. Brand new battery, extremely clean TB, cleaned the IAC sensor as well (was pretty gunked up) and new air filter and spark plugs.

I'm having the same issue. One difference is, this doesn't seem to only be on cold start up for me - I can drive around for 15-20 minutes, idle in the driveway, and it'll start doing it. It doesn't go away, but only appears if I idle for over 30 seconds.

Can anyone else confirm that the O2 sensor replacement seems to have fixed it for them? I'd hate to spend money on sensors if it's not going to fix the problem. It's good to hear that it fixed it for Dodgeric though.

 

It worked for Eric99Ram who'd been hunting down his crappy idle problem for a year, and for various other users who can be found by doing an advanced search for "oxygen sensor" limited to the 2nd gen forum.

The symptom you describe is consistent with the end of life failure mode of an O2 sensor. It may not be that, but the symptom is consistent.

 

Just to update: Replacing the upstream, pre cat O2 sensor did the trick. The only problem I encountered was when a previous owner replaced the same O2 they totally jacked the treads so I had to have the treads re-tapped. Thanks to all who made the suggestions.

 

Glad to hear it!

That sucks. But the problem is solved, so it doesn't suck too badly.

Thanks for the follow-up!