OK... I got some good help here when I was converting my 5-wire VX O2 harness to support a 4-wire O2 when I first swapped in a B16. May car has since seen a supercharged b16, then a turbo b16, and now I have a built b18c turbo.

My problem is that this time I wanted to use the engine harness that came with the b18c rather than the modified one from the VX. Now.... I have the O2 code again.

anyone here know how to connect the GSR engine harness to the VX ECU harness so that the 4-wire o2 works? Should it be as simple as just connecting the GSR harness? If so, then that makes it easy... maybe a bad o2 sensor.

HELP!!

 

you might want to try posting this in engine-tech. maybe one of our trusty mods can copy this post in there for you

 

so you're running a vx ecu with a B18? Why?

 

All the vx swaps I've done, I've just plugged in. Then again I've never seen a 5 wire o2 except on wideband a/f gauges. I'll copy this for you.

 

Bakeoff:

NO, I'm running a Hondata modified GSR ECU (P72). Here's some history.

I originally did a b16a2 swap (JDM), keeping the wiring harness from the VX motor since it had VTEC connections already. The VX had a 5-wire o2 (or LAF sensor I've heard it called), so I modified the original VX engine harness to use a 4-wire o2 (since I was now using a P30 ECU), and added the wire for the knock sensor (VX has no knock sensor).

Now, I have the B18C and I'm using the engine harness from that motor simply because it's clean (no modifications). My problem is that the harness that runs from the engine bay to the ECU is still the VX harness, so the wiring for the O2 sensor on the engine harness don't match to the proper pins on the ECU harness.

I'm thinking I'll just go ahead and replace the harness that runs to the ECU with a GSR harness. This way all of the wiring will be clean and unmodified. If push comes to shove, I'll just put back my modified VX engine harness since it worked when I had the B16 installed.

Anyone know how difficult it is to remove the ECU harness from the car ?

Thanks....

 

It should just clip in with no difficulties.

 

Hey... for future reference.

When connecting a GSR engine harness to a CIVIC VX chassis harness, the knock sensor has to be added and D14 on the chassis harness has to be moved to engine connector C22 #2 (red/white wire).