Picked up a great little OBDII Digital Code Reader made by Innova at Canadian Tire today.
And it was only $100.
I was amazed at how many codes the computer on this car can throw.
Over 600 Generic and 300 GM specific codes.
I needed it to diagnose and turn out the CES light on the dash. Once it tells you the code(*) you can erase them if you want.
The code turned out to be P0128 - Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
A consequence of running with a drilled 180 Thermostat.
Seems that you can't do too much with these '96 and newer cars without the computer letting you (and your service manager) know.
I'll keep on playing with mods for this car until I throw a P1257 code (Supercharge System Overboost)

Actually I don't think you will get that code unless there is something wrong with your boost bypass valve or something. I know on a GTP you never do. My dad runs a 2.76" Pulley on his GTP and has never gotten that code before.

By the way, I would've purchased a scan tool instead of just a code reader because a scan tool will let you check you DTC'*, and let you see how much Knock Retard you are getting and such.

And yes, it is VERY easy to get the code that you got. It came on after 20 minutes of driving my moms car after the installation of the drilled 180. Although, it hasn't come on since. Hmmmmm.

That is sooo true....A customer at our dealership tried to get his engine replaced under warranty for "so-called" premature failure of the valve train. Well after the Tech hooked up a Tech II Scanner, we soon learned, much to the customer'* dismay, that he had the engine red-lined for quite awhile, then the valves started to float, then they bent! Let'* just say the customer ended up paying for the whole bill to replace his engine. A note to the uneducated, don't try to lie to a GM Service Department!

Hey, is it a possibility that Deathrat is really just that.....hmmmm..
Maybe he'* a warranty spy for GM, logging all the mod data for guys like me who are still under warranty and do some tweaking.
Nooooo. Just a moment of insanity.