If you are looking at the CRX SI motor from the BACK (staring at the intake manifold) there are four electrical sensors. Going from left to right I believe they are:

air temp sensor (left side of intake manifold), tandem valve control solenoid valve, electronic air control valve, then throttle position sensor (far right).

Is this correct?

 

I would have to agree with your assessment.

L.

 

thanks lelopez. then I have a new question.

Doing a DX to Si DPFI to MPFI swap and there is no plug on the DX wiring harness that will plug into the SI tandem valve control solenoid valve. Is this sensor not necessary?