I have recently swapped my engine with the same model (D16Y8) I accidentally plugged the 2PIN connector for the IAC into the PSP and vice versa and drove like this for at least a month with CEL on. When I had finally discovered that that was the issue, I switched it back, but I have the code P1508 (IAC Circuit Malfunction). I have followed the instructions in the service manual which included testing the 2 pin connector for voltage, which had 12V. A12 to ground also had voltage (10). The IAC clicks when jumping A10 and A12.

I got a new ecu and IAC and the problem persists. I checked for continuity on the yellow/black from the connector to the ecu to the connector going into the IAC. There is continuity. Now for some reason there is no continuity between the blue/black on the IAC side to the ecu side, however if I test the blue black on IAC side to the yellow/black on the ecu side there is continuity(if this is confusing ask me to elaborate). Any reason for this? Also another thing to mention is that the motor that I put into my car came out of an automatic and I had to swap fly wheels on the engine because I have a manual transmission. When I did the swap I had to switchintake manifolds as well. Does the automatic vs manual intake have different specs for the IAC? Is there any difference with wiring on these two motors? Both are the same model (D16Y8)