I bought my car in 03 and have had a popcharger on for about 2.5 years, never had a problem. My hunch is it may have something to do with your MAF like someone has mentioned.

 

it only happens under those conditions (after WOT, and put car in neutral) once in the blue moon...

 

Yeah, I've definitely heard MAF. And actually I guess I've only had it on for probably about 8 months and I haven't oiled it yet, so I know it's got nothing to do with over oiling. It happened when it first got put on and it's happening now so I don't think the oil will have anything to do with it. I'm just slowing down with the clutch in now, instead of putting it into neutral. I just hope this doesn't effect me when I take it to the track, cuz that will be a pain in the ***. I'll take it out and clean it and see if that helps.

 

It sounds like the maf doesnt like something, maybe a different maf for different years?