I am no mechanic, but i try. My Ram is throwing codes for high voltage on both O2 sensors and occaisionally heater circuit malfuntions on both as well. This has been going on for about 3 weeks, and it is progressively running worse. In this time, i have brought it to a mechanic who told me the computer was bad b/c there was some voltage being sent to the O2 sensors through a lead that usually has none. So, I replaced the computer as well as a few other parts: Idle air control valve, throttle position sensor, Manifold absolut pressure sensor, charge air temp sensor, fuel pump and pressure regulator, purge soleniod, and cleaned thottle body. The only thing on the outside the motor i havent replaced is the camshaft position sensor and the damn injectors! Upon stopping, the idle drops down to around 500rpm and gets lower and lower until i finally cut it off. Every now and then, I'll put it in nuetral when it's acting up at a stop and it will hesitate and then idle itself up and pull out of it; however, if i do kill the engine it cranks back up fine and maintains proper idle. Recently the engine feels like it's going to die while driving too. Acceleration will pause and rpms will decrease, (accelerator position constant) or it will pause then take off, or it will just jerk back and forth between wanting to die and hall ***. I'm about a grand into this little overhaul project and out of hair to pull out of my head. Any suggestions would be greatly apprieciated!!!

 

have you replaced the O2 sensors? if not you need to.
then probe the wires for 12v on the whites (heaters).
ground on one. color?
low volt signal on the other.

you need to get rid of the codes before chasing the idle problems. a false O2 signal can cause all kinds of problems. the fact that it straightens out upon a restart suggests that it gets confused in closed loop mode (warm operation), and then straightens out in open loop (startup/warmup).

idle is controlled by IAC and TPS. i see you replaced those. check the port on the back of the TB that the IAC fits into. clean with brake cleaner or carb cleaner.