I picked up a 74mm throttle body today at a local junkyard (came off a E55 AMG ), gently cleaned the throttle plate with some isopropyl alcohol, and got it swapped out. I followed the PDF guide by Rekcah. I performed the throttle reset and started it up.

It started by idling a little high (~1000 rpm). After a few seconds it shot up to 2k and started "surging" between 1.5k and 2k.
I checked every connection and hose in the immediate area and can't find anything loose.

I tried to drive it down the driveway but, it was completely undrivable with the revs bouncing all over the place.
It threw a CEL after a while and gave me a code P0100: MAF or VAF Circuit Malfunction.

The guys at Advance Auto Parts recommended I test that MAF sensor by disconnecting it, then starting the car to see if it runs any different. I did that, and it just stalled out immediately after starting. Should I assume that the MAF is good?

My other mods are TVT intake, magnaflow exhaust, and a Eurocharged tune if that helps.

Any suggestions?