2004 Dodge Ram 2x4 SLT 4.7 80,000 mi.
About 2 years ago the engine seemed to have loss some power, I replaced all fluids and gave it a tune up. Still didn't run just right. The engine and transmission seem to be confused. While I sit at a light my RPM's will drop below 500 (never stall) While accelerating the transmission will move up a gear even though I haven't let back on the peddle or am going up hill, I will floor it to get down a gear and It will almost immediately move back up a gear. about 3 months ago I read to replace the TPS and my god It fixed it! Truck ran brand new and about a week latter it runs exactly the way it did before TPS replacement. I got a warranty TPS from Advanced Auto and it lasted about 3 days, and the third one didn't fix my truck at all. Before I spend hundreds of dollars on sensors, do you have any ideas?

 

Have you disconnected your battery and switched the headlights on?
If not, do so. The PCM doesn't always recognize the new sensor unless you reset it.
Check your TV cable too. (throttle valve)
It controls the throttle body when the transmission shifts.

Best of luck!
Oh yeah, WELCOME TO DF!

 

I have disconnected the battery and turned the ignition on for 1 min. Also have left the battery out over night. Yesterday, I watched a video about a Ram Diesel that had "dead Pedal" He was trying to reset something by turning the ignition on and pressing then depressing the gas peddle once over 1 minute. I tried this this morning and also with the truck off pressed the peddle to the floor and back about a hundred times. For what ever reason the truck runs amazingly better, but for how long. Sounds like something somewhere is sticking, right? Maybe the IAC valve?

 

The IAC would not be affected by pumping the gas pedal.
The IAC controls idle. What you may have done there is loosened up any carbon on the TB and possibly reset the TPS (throttle position sensor) in the process. Good job.
Now we wait and see if it comes back. lol