B20 in my DC has been giving me headaches. It wouldn't stay on after it fired up unless you gave it some throttle. For the longest time I wasn't getting a code but today, in an attempt to bleed the cooling system, I was finally able to get a CEL. I got code 43.

Stock B20, obd1 LS intake mani, chipped p28 w/skunk2 non vtec program.

Since then, I have swapped out the 02, fuel pump and fuel injectors and I still get the same code.

I then borrowed a stock LS ecu from a buddy and tried it out. Now I get a code 14 for the IAC (EACV) - idle air control valve .

I swapped it out with another one and I still get the same code. I go back to the chipped ECU and I still get the code 43.

WTF do I do next?