could be a number of things first tap on your mass air flow sensor while it is idling and if it lines out change it. or it could be your IAC (intake air control)
if the 94 probe is a GT, yes.the 2.0l alternators are different from the GTthe autozone part numbers for the 94 2.0L Probe is 14449 and the part number for the 94 2.5L GT is 14450