I have a 95 ram 4x2 w 5.9 gas, when it sits for the night and I drive it in the morning it runs fine for 30 min or so but after that it will missfire and gets herky jerky and also wants to downshift out of od, the cel will also ussually flash. I did a tune-up= plugs, wires, dist cap, and rotor, and just replaced the IAC but it's still acting up. If it gets 4 or 5 hrs to sit not running it will drive fine for 30-40 min. Do I need a new PCM? I need your guys expertise, please.

 

Pull your upstream o2 sensor. While it's cold, drive it around the block, see what happens. Your o2's might be screwed up.

Checked your plenum yet? Welcome to DF.

 

Is the upstream O2 on the engine? cuz I had the one on the exhaust replaced last week. Thnx for the welcome I love this site.

 

I pulled the tb when I replaced the IAC and looked in the intake and it seems ok especially compared to the plenum plates i saw on the end-all be-all plenum thread.

 

The upstream o2 is before the cat.
IIRC 95's only have an upstream. And just because your plenum doesn't look bad doesn't mean it's alright. Mine was the same way, yet it was way blown.

 

About two weeks ago my friend thought maybe the cat was clogged so we cut it out and crafted a y connector then I took it to Davis auto and they put a new O2 sensor in where the cat would be free of charge. Would a plenum leak cause the engine to missfire, get herky jerky, and want to downshift out of od?

 

Keep in mind it was having these problems before we took the cat off and is still having them after the fact.

 

Yup. It causes a massive vacuum leak, and not run right.
Mine was so bad, it actually sounded like I had a vacuum hose loose.
Does it missfire in OD? When does it buck real bad? Is it all in OD? If so, you might need to re-route your plug wires per the TSB somewhere around here....gimme a minute to find it...lol

*EDIT*
here
https://dodgeforum.com/forum/2nd-gen...lug-wires.html

 

It will do it in od then kick down a gear continue to do it then kick back up to od still does it back and forth then it just decides to not go back in od, and the electronic od button on the dash indicates od is turned off. Ussually the cel will flash at a pretty fast pace but not always.

 

Flashing CEL is usually indicative of an o2 issue, but you have no cat.

Drives fine in all other gears?