i just recenlty bought a 98 ram 1500 with the 5.2 and ive had a few minor problems with it. one that i havent been able to figure out is a chugging problem it has.

when i go start it to warm it up after work it starts chugging after about a minute of idling. if i bump the gas when it starts chugging, it comes right out of it and idles fine after. rpms at normal idle are about 800 +/-, when its chugging, the rpms stay about the same, maybe 750 +/-. if i let it sit it will eventually come out of it by itself after about 1-2 minutes. it sounds like the engine wants to die but it never does, but it shakes the truck pretty good when it starts chugging. engine seems to have good power when i drive it. for some reason it only happens at night after work (not saying the time has anything to do with it).

In the morning before school i start it and it idles fine, no chugging. when i start it after school to home, no chugging. when i start it up to go to work, no chgging. when i start it up to leave work, it starts chugging. im thinking the time relationship has to do with how long the engine sits in between start ups but im not sure.

i pulled a code: O2 sensor high voltage bank 1 sensor 1. not sure if that has anything to do with it. i plan on replacing it soon.

not sure where to go with this. i thought about the iac but i've been leaning away from that as time goes on. any input will help.

 

Sounds like a pre-cat 02 going out.

But that's my thought. Check your plug wires too and make sure they're not leaking or crossfiring.

 

If you stick a new 02 sensor in , get a Denso or NTK. What does it do if you call in sick?

 

Could try running it with the pre-cat sensor unplugged for a day or so, and see if that makes any difference in cold idle. If it does, you found your problem.

 

i'll try running it with the pre-02 out on monday and see what it does. the plug wires are new about 1,000 miles ago and separated. i followed the tsb for wire routing on them also.

 

Why did you rule out IAC? Remove it and clean it to see if it helps.