Hello I have been having some issues with my truck idling, my truck is a 03 dodge ram 1500 quad cab, short bed, 2wd with the 5.7 liter hemi. It has about 139K miles on it and it is pretty much completely stock, the only "modification" it has is a cat back dual exhaust with a cherry bomb muffler that has been on the truck for about 6 months and 3500 miles.

The issues have pretty much just started about a week ago when the temperature has dropped below 10 degrees Fahrenheit, I have had similar issues only twice in the past but they only happened once over like two months and I couldn't replicate the issue to figure it out, but now it has been going on for pretty much the whole week and they are much worse. Any way on to the problem, the truck has been idling kinda rough and it seems to fluctuate up and down about 200 rpm between 500 and 750 ish but it dips to 500 or lower from time to time and it has even stalled on me 3 times and when it would stall the rpms would drop and the dash lights would dim. The engine light came on and my scanner would not give me a code but when i did the "key dance" it gave me the code p2110, after some searching around I found a dodge service bulletin, that said the throttle body can have issues in the cold so I ordered the replacement updated throttle body number 5161805AA form my local dodge dealer. I removed the negative throttle cable for the half hour or so it took me to replace the throttle body and when I reconnected the cable the truck fired right up and idled perfectly fine, I backed the truck up and left it running well I checked the tire pressure and filled a couple of tires, but when I hopped back in the truck the check engine light was back on and I checked it and it said down stream o2 sensor bank one sensor two, but the p2110 was gone.

I took the truck for a test drive after replacing the throttle body with the check engine light still on and it was going fine but once the truck got closer to operating temp it started to act up again, I came up to a stop sign and the dash dimmed a little and I could see the rpms getting low dipping slightly under 500 but I was able to get moving before it stalled, but as i was turning to go down my street I felt the power steering stop and it had died on me, I was able to shift into neutral and fire it back up before I stopped moving and I parked in my drive way, it was idling funny again and bouncing up and down again between 500 and 750 but I also noticed that my voltage gauge was bouncing as well but it seemed to be going up as the rpm dipped but I might be backwards, I bumped the throttle slightly it smoothed out the idle but I shut the truck off slight after. The o2 sensor code is still there but the p2110 has not returned at all even with the jumpy idle and stalling once.

I am going to have my battery tested tomorrow to see if that has any issues, I have been lurking around and found the hemi doesn't like weak or bad batteries but as of right now I am kinda stumped and cold, I don't have a garage and it is about 5 degrees out so working outside has its down sides. Sorry for the wall of text but I wanted to make sure to provide as much info as I could to help you guys help me, also thanks in advance.

 

I was gonna ask what the battery condition was. Have you had it awhile or is it a recent battery?

 

Well my battery was low, rated for 800cca and it was putting out 400, replaced the battery with an auto craft gold 850 and it seems better so far but I have only done one one trip home from work and it has "warmed up" to 25 degrees this morning it was -7 and it was not happy it stalled just as I got into work but I'll see how the new battery dose, also the o2 sensor code is p0138 but now that the battery has been disconnected it has disappeared for now

 

I would also check your alternator. I had something like that happen to me and a couple weeks later on a very cold morning (about 5 degrees) i started my truck up and the alternator went out on me.

 

Well I drove to work this morning in about -5 and I got to work without stalling or having the rpm drop below 650, plus the trip home and a third to the store but those were in 30 degree weather, for now I am cautiously optimistic, but the p0138 code has popped back up so next it is time for an o2 sensor. Auto zone tested my alternator starter and all of that and said that that part seemed good and it was about 10 at the time, the temperature has been jumping around like crazy the last few days. One more question, how many o2 sensors dose the 03 hemi have, I have only been under the truck a couple times and I only remember seeing one cat and one pair of 02 sensors but I have been wrong several times in the past and I'm sure it will happen again, plus I think the parts store says I have four o2 sensors but they aren't always the most informed either.

 

Just read this on another forum.
Maybe it might help if your problem resurfaces??

"2003 Dodge Ram 1500 Idle Problems - SOLVED
I wanted to post what helped me in the event it is useful to someone else.

Symptom: 2003 Dodge Ram 1500 Hemi randomly shuts down at idle, but always restarts without a problem.

Attempted Solutions: PCV, EVAP, Throttle Body, Cam Position Sensor, Fuel Pump

Ultimate Solution: Alternator

Conclusion: My alternator had a very interesting failure mode wherein at idle it would internally short its regulating circuit to ground. This pulled my bus voltage low and caused an instantaneous shut down as if the key was turned off. I replaced my stock Bosch 136 amp with the 160 Amp plow alternator and the truck has run beautifully every since. It is likely that it was a combination of problems that made the idle so weak (although it is already very low by design) that the bus voltage drop killed it. However after the new alternator she is running like a kitten and idling happily again.

Hope this helps someone save money and time"

Al.

 

Thank you, I think it might be my alternator as well, I got to work this morning and my idle dropped again to about 400-450 ish and it was not happy, I noticed my voltage gauge was also down to pretty much battery voltage so perhaps my alternator is starting to randomly cut out on me.

My battery was so weak maybe it wouldn't keep the truck running when the voltage dipped, but so far it has not died again just stumbled at idle. I might pick up an alternator next and clean any and all grounds I can get my hands and tools on. Only slight difference is that mine would idle low and would kinda sputter to a stop vs turning the key off like described, but I'm starting to run low on options, and i'm getting the feeling that this is electrical based but I'll be sure to keep updating you guys and let everyone know when this is over, one thing that drives me nuts is finding a post with similar issues but the post died with no answer of what fixed it

Thanks for all of the help so far guys.

 

I would like to update with a fix but so far I have just been kinda waiting and driving, it has not been terribly cold here it has been sticking to the mid to upper 20's and things have been pretty decent so far, it has not stalled out again but the rpm has dropped once, my new o2 sensor showed up but it was the wrong one and now that has to go back and be swapped out, but strangely enough my check engine light has disappeared, i'm still getting the correct sensor just to have on hand in case the light comes back on but so far so good, but once the weather drops back to single digits i'll see if the gremlins come back, even so new 160 amp alternator on its way just time to play the waiting game.

 

I’ve got the same problem with stalling on petrol but not on gas. Stalling and weak bank both sides. I’m struggling

 

Erm, what's the difference between 'petrol', and 'gas'??