2000 dodge ram 1500 5.9L got code p0108 changed map sensor, throttle position sensor, and idle air valve. same code runs rough on idle and stalls. I'm going to check for leaks but can anyone tell me the next step to take?

is that when you disconnect the battery and the power drain out? yes

I have seen many old posts on this subject. A lot of guys say it's due to a bad battery. Put a volt meter on your battery without the truck running. If it says 10.8 or something lower than 12, that may be your issue. A plugged EGR will cause poor idle also. On rare occasions, it can be the radiator temp sensor, or ambient air sensor. If they malfunction, they can be telling the ECU that it's very cold, and it could be dumping too much fuel, or too little depending on the malfunction. You will probably find that you have a bad intake leak someplace.

ok so you changed the map and the same code is active....P0108 (MAP sensor voltage high) ....means that the PCM sees that the voltage is not being used..... what you have to do is check to make sure you have 5 volts and ground at the map sensor and ohm test the sensor return from the map to the PCM just keep in mind that all three come from the PCM (Power control module) and that all sensors share the same 5volt reference at splice s119 and ground at splice s118 see the pic ...I would think that you have an open on the sensor signal or a bad PCM

by disconnecting the battery it will erase the codes from the PCM memory and will also reset all of the adaptive memories for the sensors to factory specs but if you have started the vehicle with the new map sensor more than three times since replacing it then the MIL light should have reset on its own and the code should have went to stored