I recently swapped my 95 DX Hatch from my mini-me setup (b7/z6) over to a D15Z1, looking for better mpg at the moment. However, at the time of the swap I was only able to find the sub harness from the VX, the harness from the strut tower that plugs in the sensors and tranny, etc. I am using my stock DX harness from the strut tower to ecu, I noticed I have an extra plug from the VX harness left over, I researched and found this was common. I had it running smooth on the P28, until it warmed up, which I figured was running open loop until it warmed up and when it switched to closed, it couldn't read the 5 wire o2 sensor.

So today, I got my P07 in, hooked it up, and am now getting 3 codes, 2 of which I had when using my p28, they are CEL 41 (primary o2 heater filament) and CEL 21 (vtec oil pressure switch), now I'm getting CEL 22 (vtec solenoid) with the other 2. I have no CEL for the EGR.
My question is, or assumption, correct me if I'm wrong, the 2 harnesses I have shouldn't be put together, as in some wires aren't going to the right destination. My car will turn over, will attempt to idle, very roughly when it does, and blueish smoke from exhaust, which is probably from the old catalytic converter.

I found an uncut complete VX harness, should I go ahead and save me a bunch of trouble and just replace it with the for sure right harness, or am I overlooking something simple here.

 

You found a complete uncut VX harness? Wow - that is a good find. Yes, use that, definitely.

 

Word, I have access to another DX harness, all I would have to wire myself would be EGR, the 5wire o2, and the vtec solenoid?

 

do u have the 5wire o2 sensor to go with this?
i don't think you'll get the uber gas mileage without it..

 

Yeah, I already have the 5 wire o2. Turns out that VX harness didn't come with the shock tower back to the ecu. I doubt I will be able to find a full VX harness anytime soon. So what is my best option?

Should I go ahead and get a full DX harness and just do the wiring myself, or should I find a VX harness? What I have now isn't working, which is DX harness from ecu to shock tower, from there on is a VX harness, and on the shock tower I have one extra plug unused.

Basically, how many pins would I have to wire up if I were to run a full DX harness? From what I understand, it's one wire for the o2, one wire for the vtec oil pressure switch, and then the EGR, which I'm not sure what all needs to be done there.

 

Use the VX harness to the shock tower (since you have that now). Then, you will add your other wiring.... your list is good, but may be incomplete ... I really don't know. To be honest, H-T is not the best forum to be discussing VX stuff. The real gas miser geeks are over at gassavers.org, and another forum which I'm forgetting the name of atm. Also, you could PM the user TomO on this site -- he's a VX superpro.

 

I just did a CX to VX swap in my DD three weeks ago. I went the expensive route and sourced a used VX engine & main cabin harness. There are a few out there but you have to make some calls and be willing to pay the price if you find one.

The CX/DX does lack the fourth main cabin harness plug as you found. Think it is a 10 pin plug (can't remember exactly). I know the 5-wire O2 wiring is housed there. A SI/EX harness will have the plug if you can't source a VX. While the wiring colors may not match, you should be able to use it for your build.

You will also need a 2-pin plug for the EGR Control Box (assuming you have sourced this). This is actually part of the VX Passenger Side Engine Harness. I was fortunate and cut this off my buddies' VX harness since it wasn't being used for his B16 swap.