This is one of my first post because honetsly I usually search and find my answer.

So had an idea that my plenum was going by loss of power, poor MPGs, had a P0420 code come and go. Then out of the blue got a p0300 and p0302 code. Well lets get all this fixed.
I figured the plenum was causing the P0300 and the p0420 (clogged cat).
I spent all day repairing this, followed directions with the hughes kit to a T. Looked at a couple threads helping me with the install too.
I also removed the distributor cause the cap bolt broke off in it. Marked everything and put it back together. So now everything is back together and it started right up(YEA!)and then died. Checked everything three times. Obviously Im missing something, but let me explain what Ive changed and other symptoms.

New hughes plenum kit
New Cap and Rotor(brass)
plugs and wires
and PCV

I plan on haveing a new cat installed this this week and have new NGK 02 senors too just haven't installed them.

Now it would crank and start but never idle more than 10 seconds. It would drop down and die every time. I tought it was the IAC, so bought a new one and......nope. Still doing the same thing.
This is where I get lost. I pulled the hose out of the PCV and it will idle.... let it run for a couple minutes just to make sure...as soon as I plug the hose back in it dies.
The only code I have gotten is a P0123 which I think I caused when I let the truck in the on postition not running and unpluging the sensors on the TB. And now I got a P0320. Im so tired Im out of ideas too. Any help is greatly appreciated.

2002 Dodge Ram 5.9L 1500 4x4

Thanks Matt

 

You need a scanner to set the timing for the 5.9 engine, no timing lights. You need to set the sync timing to 0 to 5 degrees. The P0420 code maybe from an exhaust leak or one or both o2 sensors.

 

Thats what I think I did.
I think I messed the fuel sync up with the distirbutor being slightly off.

 

I have the same issue, I have a 2002 dodge ram 1500 5.9L, My truck sat for 3 days and now as soon as I start it up it dies right away. If I have my foot on gas she will run, but it wont idle without shutting down, no fault codes and the battery and alternator are reading perfect, I have some carbon build up in the throttle body but not a lot, I was told to clean the IAC or even replace it, but this happened over night literally !