And I have a Monte with almost 170K miles on it, and I'm still rocking 34 MPGs

After modding the car, and not tuning for the mods, you won't really see much gas mileage changes. Your stock PCM can only learn so much.

 

34 mpg is amazing, I envy that. I was thinking of getting a ZZP PCM program to get my EVAP and rear o2 deletes done. All I have left is downpipe w/ high flow and corsa cat-back. I don't really want too much of their "performance" changes, but would like something more for better gas mileage. Some new kid just posted in the welcome section he works there at ZZP, I'll have to ask him I guess.