Well in the first 3 months of 2002, they still had LD9's (2.4L Twin Cam)in them... after that, they all had 2.2L Ecotec's... but if it was an Eco, it would be a LS Sport. So you have the 2.4 if it really is a Z24.
Do you know the code that the ECU was reading out? If you can get the code, i could find out exactly what you need to fix.
Im not a big fan of GMs factory electronics with this engine to begin with since i build these things anywhere from mild to wild, but at the same time, i know them like the back of my right hand so.