Intermittent rough idle, stalling, rpm searching 6.4 Hemi

[GoLikeHellMopar]

I have a 2015 Ram 2500 crew cab laramie 4x4 that has been having intermittent running issues. Currently have 81,*** miles on it and over the last two weeks it has randomly started to have choppy idle, while searching for rpms, and then stalls out. This has mostly happened when parked and only one time where I was driving down the road where it died and could not get it restarted. I had it towed to the dealer after I went through trying to find connection or other issues I am familiar with. Once the dealer actually looked at it, sitting for 4 days, it fired right up but ran "alittle" rough. Then it started running just fine. There were no codes when it stalled but the service electronic throttle control came on the dash. The only thing the dealership found was that it threw a code for bank 1 and 2 02 sensor out of range and it lost communication once to pcm. After them "looking" at it for 3 more days, they could not find any issues and it was running fine. They said they connected all the connections for main wiring harness and could not find anything. I drove it home with no issues and drove it several times over the next week. The weather was around 20 to 40 degrees with no precipitation while all this was going on.

Once home, I did several checks for grounds and wiring harness connections at the pcm, sensors, etc., with finding nothing loose or issues. I opened up the fuse panel and made sure everything was secure down for fuses and harness. I did checks of hoses, etc. for any kind of vacuum leaks, and found nothing. I tightened down the intake 8mm bolts, which I have done before, and nothing was overly loose. I decided to go ahead and change out the front 02 sensors myself ,based on mileage and low cost. It seemed to run just fine. I cleaned the throttle body as it had some build up and a little bit of oil. I threw in a standard paper air filter to rule out any kind of oil interference that some could say coming from the standard airbox K&N filter. The K&N has been in there since 3,000 miles and cleaned every 20K. I found no miss fires logged on the scan tool while watching live data and nothing stored.

After not driving it for two days, I went out to run and errand. It started fine but then went back into a choppy idle and then died out after about 20 seconds of searching for an rpm. It started right back up but then died. You could smell it running rich and I also smelled a hint of oil. I looked at connections for maf, map, iat, throttlebody, battery, etc. and found nothing. I pulled the connection to the MAF and it popped the service throttle control error on the dash. I also pulled the MAP sensor and it lit the CEL for a MAP sensor out of range. I just back in and started it up, and now running fine. I plugged both the MAF and MAP back in and still runs fine. I cleared the codes I took it on a run and it is not in limp mode and idles fine. Battery is full charged, full of fuel, 35 degree weather no precipitation. I turned off the the heat / defroster when it started to choppy and nothing changed. No missfires registered on scan tool

Any ideas on what else I can look at or missing for this intermittent?

Truck has always ran smooth until at 72K, about 6 months ago, the MPG started to drop from just below 15mpg to 12.5 to 13 all the time. One day I left to go to work and it seemed like it was going in and out of limp mode after I got a mile away from my house. It was a standard warm summer day. It cleared it self up as I was turning around to head back home. I checked and there were no codes, no misfires, or nothing else as I backed into my garage. I shut it off and went under to see if I see anything or find anything else. I started it back up and it was the choppy idle and then stalled out. I could get it started but loopy idle and die out. I took a shot, based on something I experienced with another 1500 with the 5.7 hemi, and changed out the MAP sensor. As soon I did that, it started and ran fine. I decided to change out the plugs at that time too. It had been running fine until this happened at 80K

I appreciate any ideas.

 

[Mojo88]

I didn't see you mention anywhere that you actually cleaned the MAF? I've got one vehicle that is especially sensitive to that issue, and when the MAF gets even slightly dirty, it acts like yours. Then I get out the MAF spray cleaner, give it a bunch of heavy shots, re-install it, and engine runes like new again.

 

[GoLikeHellMopar]

Thanks for pointing that out Mojo88 on the MAF as I missed saying that I changed out the MAF to a new one when I can changed the MAP sensor from my 5.7 Hemi experience. It is an aftermarket Delphi that I put in at 72K. I was reading up that there have been problems with aftermarket MAF sensors and MAP sensors. I have been trying to find OEM units from local dealers and both gave me the run around for multiple weeks. I just looked on RockAuto and it looks like they have them so I was going to order it. Thoughts?

 

[Wild one]

Thanks for pointing that out Mojo88 on the MAF as I missed saying that I changed out the MAF to a new one when I can changed the MAP sensor from my 5.7 Hemi experience. It is an aftermarket Delphi that I put in at 72K. I was reading up that there have been problems with aftermarket MAF sensors and MAP sensors. I have been trying to find OEM units from local dealers and both gave me the run around for multiple weeks. I just looked on RockAuto and it looks like they have them so I was going to order it. Thoughts?

This won't be your issue,but pull a couple coils and pop the boots off and see if the spring and resistors under the springs are corroded.The contact points can be cleaned ,along with the springs .I doubt it'll be your issue,but it's always worth while doing a bit of maintence on the coils when you do a plug change

 

[2003F350]

Thanks for pointing that out Mojo88 on the MAF as I missed saying that I changed out the MAF to a new one when I can changed the MAP sensor from my 5.7 Hemi experience. It is an aftermarket Delphi that I put in at 72K. I was reading up that there have been problems with aftermarket MAF sensors and MAP sensors. I have been trying to find OEM units from local dealers and both gave me the run around for multiple weeks. I just looked on RockAuto and it looks like they have them so I was going to order it. Thoughts?

Yeah, this happened to me when my MAP sensor completely died. No code thrown, truck had extremely rough idle at ALL RPM ranges, but managed to keep running until I got to the dealer, where it stalled out and wouldn't restart. With no codes and not running their tech didn't think to unplug MAF and MAP to see if it would start, probably would have. Mopar engineer ended up figuring out the issue, a new MAP sensor (which took like 2 weeks for an OEM one to show up) solved the issue.

I don't know about Ram, but I know Ford vehicles perform better with OEM electrical components. For whatever reason aftermarket components tend to fail prematurely, if they function properly at all. It could well be this is a component on Ram trucks that acts the same way.

 

[NCRaineman]

I don't know about Ram, but I know Ford vehicles perform better with OEM electrical components. For whatever reason aftermarket components tend to fail prematurely, if they function properly at all. It could well be this is a component on Ram trucks that acts the same way

Given the amount of Chinese garbage on the market today I'd go OEM and only OEM. Even then you have to be careful if not ordering from a dealer. Third party sources often end up with counterfeits and don't even know it.

 

[Mojo88]

Thanks for pointing that out Mojo88 on the MAF as I missed saying that I changed out the MAF to a new one when I can changed the MAP sensor from my 5.7 Hemi experience. It is an aftermarket Delphi that I put in at 72K. I was reading up that there have been problems with aftermarket MAF sensors and MAP sensors. I have been trying to find OEM units from local dealers and both gave me the run around for multiple weeks. I just looked on RockAuto and it looks like they have them so I was going to order it. Thoughts?

As already stated by @NCRaineman , if I was gonna buy new MAF or MAP sensors, I would buy only OEM. Try one of the online Dodge parts dealers, like this one: https://parts.allmoparparts.com/

Honestly, I would just try a MAF spray clean first. You may have some of that spray laying around, so it wouldn't cost you anything. This (dirty MAF) would be especially likely to be the issue if you were using an air filter that is oiled, as tiny oil particles will migrate from the air filter onto the ultra-sensitive MAF sensor wires.

 

[Riccochet]

bad gas maybe?

 

[RAZ175]

Another thing to check is your intake manifold bolts. I had a slight misfire type stumble at idle. When i checked my manifold bolts, the front left was barely even tight. All others were a little loose. I torqued them all and the stumble went away. It was probably pulling extra air into the cylinder with the loose bolt.

 

[HEMIMANN]

Another thing to check is your intake manifold bolts. I had a slight misfire type stumble at idle. When i checked my manifold bolts, the front left was barely even tight. All others were a little loose. I torqued them all and the stumble went away. It was probably pulling extra air into the cylinder with the loose bolt.

Same.

 

[mtofell]

Third party sources often end up with counterfeits and don't even know it.

Different vehicle but I'm sure it's the same thing - When I did the timing belt on my Honda Odyssey I learned there are tons of fraudulent kits online (fwiw, Honda never made a kit so that was a dead giveaway). The folks on the Honda message board said basically anything bought through Ebay or Amazon is suspect. Most of the time places like Rockauto are solid but, as you say, they can even be duped sometimes. My takeaway is to never buy any parts from random online sellers.