car idles high when driven ?

I just finidhed my H/C/I swap and now when i drive the car it has a high idle sticking problem even when you let off the gas, it also misses when decelerating but runs fine when applying gas, FP is 40 with vacuum off,mods are listed below, i ran codes and the only one i get is 12, ive tried cleaning the iac, but it doesnt help , also tried base idle reset and it idles ok till i drive it then its back to beginning, set tps, set timing, and checked for vacuum leaks didnt find any, replaced all vacuum hoses when i did the swap, am going to try the surging idle checklist next any one have any ideas?

Mods

AFR 165 cc heads
TF stage 1 Cam
TF street heat upper and lower intake
24lb injectors
PMASS MAF calibrated for 24 lb
255 fuel pump
1.6 rockers
new lifters
new hardened pushrods
ARP head bolts
Adjustable fuel regulator
Fuel pressure gauge
new aluminum radiator
new water pump
new rad hoses


the only problem im having is the car hanging the rpms even when you let off the gas like its on cruise control, am thinking about buying a new IAC and see if that helps? thxs in advance

no i checked it but i got a new iac and the problem is gone, went thru the surging idle checklist and the valve had power but was sticking