JDM 98 B18B into my 98 Civic. I used a 98 CDN Integra ECU. Everything went good except I get this ecu code P1508 Idle Air Control Valve (IACV) Circuit Malfunction. I had my old D16Y8 throttle body on because the MAP and TPS sensors were damaged so I thought that was the problem. I just swapped to a new teg throttle body with a teg MAP and still get the code. I'm going to be swapping the TPS sensor today hopefully. If anyone has seen this or has any insight it would be greatly appreciated.

Cheers.

 

u probably have switches mismatched. its on the back on intake mani. near the tb.

 

I'll double check those thanks.

 

I double checked the connector wire colors and they're correct, I swapped the connectors anyway but still nothing. Swapped TPS and another throttle body but still have the code and a really bad idle. Also can't keep pedal at the same position or it starts to hesitate.

This is driving me crazy please help.

 

I don't have my second o2 sensor plugged in yet, does anyone think that my be causing this?

 

extended my O2 sensor and still nothing?

 

extended my O2 sensor and still nothing?

 

Have you tried unplugging your IACV and looking around the engine bay for another plug nearby that looks exactly the same?

Off the top of my head, other sensors that use the same plug are:

Reverse light, fan switch sensor, coolant temp sensor, EVAP, IAT, PS Pressure switch, and cruise control.