Motor swap help

[B18b1DA]

I recently swapped in a 2000 b18b1 to a 91 integra.
Here is whats inside the car:
00 Intake manifold
00 b18b1 motor
91 b18a1 trans
91 throttle body
91 distributor
91 pr4-a10 ecu
91 injectors

Heres the problem:

At cold start up the car idles really low
When engine is warm the idle fluctuates between 1000rpm and 2500rpm but when the engines cold, the idle doesnt misfire.
Check Engine Light came on with the code 14. Guessing its cuz the 00 intake manifold doesnt have the FITV.

Please help me find a solution to the idle problem

Will using a 91 intake manifold solve this problem? Does it matter if I use an auto or 5 speed intake manifold?

Any help would be greatly appreciated. Thanks

 

[superhypered]

It might be the old ECU not recognizing the newer components.. odd, it doesnt fluctuate when cold, but it does when its hot? Time for alcohol injection