Another rough idle / stalling issue

[Steve1500ram]

Hi all, firstly sorry for the long post.

I have a 2005 5.7 Hemi with approx 90000 miles which has an intermittent problem with a rough idle and stalling when coming to a stop.

The rough idle only happens when the truck is cold or when first started when warm, after a mile or so it goes away.

The stalling is mainly when cold but does also occasionally happen when warm, I've changed the plugs which seemed to cure it for a short while but now it's happening again.

My check engine light is on with the following codes:

* P0172 Fuel Trim System Rich Bank 1
* P0175 Fuel Trim System Rich Bank 2
* P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2
* P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
* P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2
* P0158 HO2S Circuit High Voltage Bank 2 Sensor 2

When cleaning the throttle body I found the seal between the resonator box and throttle body is slightly torn, could this possibly be causing an air leak and throwing the codes above? Or should I replace all 4 O2 sensors?

To complicate things the truck also runs on LPG but it seems to make no difference if I switch this off and run it on gas.

Any help would be much appreciated - it's driving me nuts!

Thanks......

 

[Redtruck-VA]

I don't have a 05 so take this for what it's worth. The seal leaking between the resonator box and the TB shouldn't matter. Since both sides are getting the same error I would trace the wires an find the common plug and clean and inspect that carefully. This should go all the way back to the PCM as it is the voltage source for the O2s. I would also check and clean the chassis and battery grounds. Did you remove the TB to clean it and did you use a non-chlorinated cleaner? Carb cleaner can damage the electrics inside and brake cleaner is what I use. I don't squirt the fluid in a direct stream where it might enter somewhere it shouldn't and use a rag and small brush to actually clean with. The rear O2s only monitor the health of the cats and do not provide input for tuning. Running rich could be a result of a bad (Front) O2s but usually this pops only on one side as it is unlikely both would fail at the same time. My guess is you have corrosion on a electrical connection.

 

[Steve1500ram]

Thanks for the suggestion, I'll try to trace the wiring back from the front O2 sensors and see what I can find plus clean any earth connections I can find.
'M not sure if it was carb cleaner or brake cleaner I used but I was very careful not to get it into the electrics.

I've just been reading about the symptoms of a faulty EGR valve and they are very similar to what I have but I don't get a code for this, could this be a factor?

Thanks again...

 

[Redtruck-VA]

It certainly could contribute since it would affect the running regardless of fuel being used.

 

[Bigdaddycodes]

I had a similar issue and it turned out that my pcm had failed, I had the same codes; same issues


Sent from the rocket in my pocket

 

[Steve1500ram]

How did you figure out it was the PCM?

 

[Bigdaddycodes]

Just came to a common denominator, for all 4 02 sensors to go at the same time is kinda fishy, and seeing as they all go through the pcm I figured it was common ground and replaced it and then I reflashed my truck, benifits of working for dodge


Sent from the rocket in my pocket

 

[Steve1500ram]

Just thought I'd post an update.......

I replaced All 4 O2 sensors as recommended by a local Chrysler dealer and it did not help with the stalling, so it went back in and they diagnosed the MAP sensor was bad ( even though the truck was not throwing a code and there was no CEL )

So I got them to replace the MAP sensor about a week ago and the truck has not stalled since plus the idle is much more steady.

Looks like that was the problem.......

 

[Redtruck-VA]

Well done, especially with a dealer involved.