Dodge Spirit reving probs

[Loud_Dav3]

Hi. My friend had a Dodge spirit and is experencing very abnormal reving (mostly too low rpms and has to keep giving it gas to keep it from stalling - automatic transmission). He has taken it to a nember of shops and they seemed to had fixed the problem. After getting it back from the mechanics the car runs sound - but the fix lasts about a week, then the car starts acting up again. he doesn't know what the mechanics have/have not done (just pays the money). Any ideas of what could be causeing the problem? Thanks.