I'm not sure if it was a posting here or a tech article but someone said "stage one" performance mod is a full-blown tune-up. My IROC had been running kind of poorly so I had one done (I don't have two days to change my spark plugs).

All I can say is WOW! The car drives 100% better. I don't race it so I don't have numbers but I can tell how much better it drives.

If you want "free power" just tune her up.

 

A good tune will make problems easier to assess too.

But just FYI changing spark plugs shouldnt take more than 2 hours (tops) The hardest ones to get are on the passenger side, and the very back ones (7 and 8).

Glad that you are done with "stage one performance" though