1997 Plymouth Voyager won't stay running

I have changed the TP sensor, map sensor and engine computer module with all new parts. It starts fine but won't stay running, unless I keep the tact around 3000. "Service Engine" light still on. Scanning it still addreses 1) baro out of range, 2) 5 volt output too low, 3) TPS voltage below acceptable minimum.
HELP, I'm LOST !