Idle issues after swapping to drive by cable

[468Blazer]

What I have: 03 5.3/auto swapped to drive by cable from drive by wire.
What I've done:
1) Took out all drive by wire components and wiring
2) Installed new throttle body for cable.
3) Wired in TPS and IAC as per instructions
TPS Gray-B46, Black-B54, Dark Blue-R24
IAC Light Green/black-R77 Light green/White-R76 Light blue/black-R78 Light blue/white-R79
4) Hooked up cable and connectors to throttle body and put in new nelson pcm tuned for the throttle cable
5) starts right up fine but after initial go the idle increase very high (to the point if in gear and on gravel you will set there and spin) in park, neutral, drive it will idle high and take 5 seconds to idle down to normal

6) getting a P0106 Map/baro ckt range/ref dtc
7) tried known good map sensor and checked for any vacuum leaks. No success.
8) Unhooked cable from throttle body and still done the same thing, high idle.
9) put in known good IAC motor and still high idle
10) if I unhook the IAC connector will run/idle fine
11) What else should I check for? Its like the computer is not telling the IAC motor to close quick enough when idleing down.
Any thoughts or suggestions on how to correct the issue.

Thanks Travis

[468Blazer]

After looking over everything again I remembered the b54 wire replaced a wire in the 03 harness. After checking pinouts, the wire replaced was a ground for the map sensor. Looked at a 99-02 pinout and found b60 empty and plugged the ground in. Everything works fine now with no dtc.