I have a throttle body question

[kb2fzq]

I recently put a BBK 70mm TB on my 2000 3.8. It did seem to add some punch to the acceleration, and the car runs great as always, except now, when I go hard thru the gears and then stop at a light, clutch in, the RPM's stay between 1800 and 2300 rpm, then gradually come down to 800, my idea of a good idle.
Any ideas what's causing that?
Oh yes...I DID reset the computer after the install

 

[SpectorV]

its the decaying idle rate clean your maf wires this will help especially if you just cleaned your K&N or have cleaned it with out cleaning the maf also, the oil gets on the maf wires and messes the idle.

on a side note unless you have bolt ons your TB may actually be costing you a little power... but regardless i would clean the maf wires with some electronic contact NO RESIDUE cleaner froma autozone or where ever it may help alot, also the IAC (idle bypass valve) is located behind the throttle body between theupper intake and the firewall its cylinder shaped it may need replacing/checking the throttle body may be throwing it off.