well, I was getting codes 12 (EGR valve lift sensor) and 21 (Variable Valve ...). I also changed my timing belt last week.

I also installed a starter kill relay where I had to cut the ignition wires. I disconnected quite a bit of harnesses in the process. One harness was the Variable Valve thing. Everything I disconnected was in the general vicinity of the Variable Valve thing and the EGR valve things.

but i know that that variable valve issue will not allow me to rev up in the 4500+ rpm range.

do you have VTEC? have you been poking around the engine bay lately. perhaps you knocked a harness out or forgot to plug one back up.