So I have successfully swapped a B16A2 into me EG hatch, 94 CX to be specific. I have a chipped P28 with the OEM basemap, motor was rebuilt by a reputable shop to OEM specs. I used the stock CX harness with injector, alternator, and IAT plugs pulled from an OBD2 harness. Rewired dizzy to OBD1 plugs, wired VTEC, and wired the 4 wire O2 sensor appropriately.

Car runs like a champ.

My issue is that I am still throwing CEL #10, IAT sensor malfunction. I had originally had IAT and IACV CEL codes, and I found that I had plugged the IAT into the IACV before I rewired the plug. Simple enough fix, I plugged in the correct one and the code went away.

I then spliced on an OBD2 IAT plug, and plugged it in to the sensor mounted on the intake. Hot to hot ground to ground, reset the ecu, and started the car. Still throwing the same code, figured I messed something up, so I switched the pins. No dice, still there after a reset. I've dug and dug and can't find an answer.

The wiring to the factory IAT plug is RED YELLOW/YELLOW BLACK. RED YELLOW is also the color found at D15 on the ECU.

The car this swap came out ran beautifully without any CEL codes, and the sensor is intact.

What the hell am I missing?

 

most likely you blew out the transistor inside the ecu, or melted the sensor. check the sensor to see if the tip is deformed and open the ecu and look for a transistor near the ecu plugs that may be burnt.

 

The tip on the sensor looked fine, though there is a small protrusion that won't come off about a 1/4 of the way down from the tip.

Is that normal? Or should it be smooth and gray for the length of the sensor.

Sorry, but this is my first exposure to OBD2 motors, have only done OBD0 and OBD1 motors til now.

 

No it isn't. IAT is red/yellow and green/white.

Evap purge is red and yellow/black.

Anything with a yellow/black wire is getting 12v switched ignition power. The IAT runs at about 5v. If you plug something 12v into the IAT sensor it will ruin it as soon as you turn the key to ON (II)

 

should just be smooth all the way down, any bumps would make me think the internals have melted. a picture of the sensor would help, but sounds like to me when you had the plugs on backwards you melted it.

 

And there it is. **** me.

Looks like I get to buy a new sensor and do some resoldering tomorrow.

Thank you sir!

 

I hope you didn't blow the ECU with the miss-wiring.

 

The ecu looks fine, I pulled it just to make sure I didn't fry anything. And not getting any new codes.

Looks like the IAT blew and took all the damage thankfully.