I have an '05 4.7L Dodge Dakota that has had an issue with rough idle for over a year now. It seems to only happen after coming to a stop at a traffic light. It seems to happen more often after having driven a long distance but occasionally occurs during shorter trips. The behavior is basically that the RPMs drop to around 500 and it acts like it might stall but doesn't. If I put it in neutral or park the idle returns to normal.
I've also had very sporadic behavior where the engine just dies completely. This doesn't seem to coincide with the rough idle but it might be related. I've also had it seem to just lose power while driving slowly after starting up and then behave normally after that.
I've changed the spark plugs, replaced the O2, TPS & MAP sensors and the IAC valve. I finally got the bright idea to get a data logger and see if I can get some better insight into what is going on. It happened today while I was logging and it looks like the voltage on all four O2 sensors goes to zero at the same time that the RPMs dip down to ~500. The only other obvious thing I noticed is a jump in the intake manifold absolute pressure as the rpms drop.
Here is a link to a google spreadsheet with the sensor data for the trip: https://goo.gl/2Uuq9u. The data of interest is around row 750 (1226 seconds into the trip).
Anyone help on figuring out what might be going on would be awesome. I'm wondering if perhaps the problem is fuel pressure related (the data logger doesn't seem to be able to measure that). On another forum, there were several suggestions that the transmission might be the culprit.