Do you know what your eng vacuum is at idle ? Are your cam and crank in sync with eng running ? You might have a bad MAP sensor ? Your eng vacuum should be almost the same at idle and 2500 rpm . Because you could have a plugged cat to ? Check your 02 sensor under full throttle, the readings are supposed to go rich under load. If not then its a fuel delivery condition if the 02 are not read right. Have you checked the inputs to your computer for fuel delivery ?
Vac at idle should be between 19 and 21 and nice and steady.
The front 02 should read full rich under WOT , between .8 and 1.0 volt, don't worry about the rear 02.
Check you cat to see if plugged by doing a back presure test , if you don't have the tester, then check the temp of your exhaust before and after your cat, with a temp gun, if cat is plugged, it will actually be pretty cool in front of cat before no air will be flowing through .
With the Back Presure Tester and put it in the front 02 sensor start your eng and take a reading at 2500 rpm it shouldn't be more then 1.5psi
Dont be just tossing in parts like most people do, because then some times you never know what caused the problems.
Take your time and do the right test !

 

Thank you for your input, but the issue has been fixed.

It was the rear O2 sensor--I described my trouble shooting in the post before yours midnite 12.

It is a common misconception you can ignore the rear O2 in trouble shooting. I ignored it myself. But I did locate several sources that explain how the rear sensor does effect mixture in Dodges. A link in my previous post.

I drove over 135 miles yesterday, all good.

I don't know how to change the thread title to include SOLVED or FIXED.

Geoff

 

.....

 

Well Hairy Eagle I don't think its fixed ! None of your symptoms are really the same to what you found in your link ? Did you disconnect your battery to install the 02 sensor ? If so all you did was clear your computer and its doing a relearn now.
The rear 02 hardly causes your problems. Out of the 26 years as a Dodge mechanic think I only replaced a handful of the 02 sensor for loss of power, and most was due to bad wires being grounded and shorted. Or from having Bosch 02 sensors installed.
Now some times people will think they fixed it after replacing something and will drive and act fine, and most of the time its from disconnecting the battery and then the PCM is in the relearn state, because it takes 3 times for something to act up to toss a code or for the PCM to react to it, this is in most cases, some times it takes a couple of drive cycles for the PCM to toss a code or react. Then some times people think they fixed it after replacing the part and later find they didn't, due to the wires they were moving around fixed the problem, due to a short and so on.
That why it is important to try to do the right tests, the right steps in diagnosing and stop tossing parts in !
We had a customer that didn't believe us when her truck kept stalling out , it was the cluster that went bad, she wanted us to start replacing parts due to what she found on the internet, that a cluster couldnt take down the whole system.
Just because the internet says something or you find someone with the same things going on, doesn't mean its the same fix !
Well hope this is your fix, but I dont think so.
Yes there are to many backyard mechanics that just toss parts on and don't know what they are talking about !

 

I hope its fixed too!

I've been driving with the live data scanner attached, my STFT have been flipping between negative and positive 3 most of the time. Long term is right around zero.

Rear sensor never reads over .9 after it heats up. Never reports an over volt.

200 miles now.

Even if this doesn't solve the issue, to me at least there seems to be good evidence the rear O2 sensor does indeed play a roll in A/F mixture. I'm having a chat and beers with a Chrysler area rep tomorrow to see if he can confirm the rear O2 can alter what the PCM expects as goal voltage from the front sensor. If he does confirm, that seals it for me.

Fingers crossed, got a full load to haul 45 miles this afternoon...

Geoff

 

Feel free to take the time and step up with the correct information when that happens.

 

Well my meet up with the Dodge rep was informative--but not in any useful way. He explained he was better versed with the inner workings of the corporate structure, than the inner workings of Dodge vehicles. Did say he'd pass my rear O2 sensor question onto a retired tech he trusts. So....

Beast still running fine, some 300 miles post repair. The front O2 is taking longer to heat up than just a few days ago, but it too looks to be original. I'll wait till it fails before replacing.

Geoff