I did the b16a SiR II swap, Y21 tranny and p30 ecu in a 94 civic coupe. The check engine light came on. Code 23 (knock sensor) did some research wired it into my ecu but I didn't reset the ecu. Do you think b/c I didn't reset the ecu that it still comes on or could it be a bad knock sensor.

 

Gotta reset the computer, just disconnect the negative battery terminal and push the brake pedal down (the lights trying to come on will drain any juice left in the system). Your ECU will remember any codes it's triggered till it's powered down or reset. I can't imagine you wired in a knock sensor wire without disconnecting the ECU though? Is it still throwing the same code. You ran the wire to D3 correct? How did you connect it to the ECU plug?

 

I had to splice the wire b/c there was a pin in d3. I took out the fuse for the ecu would that reset it or do I have to do what you said? After I wired it up the cel still came on. Then the next day I reset the ecu. Could it be because I didn't reset the ecu right away it's still throwing that code?

 

depends on which fuse you removed.
there are two in the underhood fuse box that are related to the ECU.
if you pulled the 'backup' fuse then it's the exact same thing as resetting the ECU, if you pulled the fuse that says ECU (or something like that) then you need to reset it yet. That fuse powers the ECU when the car is running.

 

'94 coupe that's already using the D3 spot? Hmm, I remember helping a guy with a VX hatch and I think the factory O2 sensor (VX's have a weird multiwire O2) used D3 and he reused to the wire to power his knock sensor and it worked but I didn't know of any coupe's with that setup. I would try resetting the ECU by simply disconnecting the battery (you gotta reset your radio presets but eh, so what). I also don't want to sound rude, but I would recheck the location that you added the wire to at the ECU. I don't think their should be a wire already in the D3 location on a coupe. I'm attaching a little graphic I made after I did my swap with the pinout locations, you can try checking against that. When I first did my swap, I just twisted the wires, shoved them through the back of the ECU plug and connect it back and it worked. I later got some real ECU pins, soldered and heatshrinked the wires to them and added them to the harness but we wired it into D5 (I couldn't remember the pin location) and had a check engine light. I haven't really heard too many things about knock sensors failing so I doubt it's the sensor itself. Hopefully this will fix you up.

 

Yeah, it's in the D5 slot instead of d3 I looked at the ecu wrong the #'s go 1 and then the next # 2 is below that one not next to it and so on and so forth. Well I'll try that to see what happens, thanks for the help guys.