d0nkey

Okay, first of all, hi. I'm new here. Starting this hobby for real this time from scratch. So here's the background on my eg hatch.

I bought it about a decade ago, it's a 94 vx with a d16z6 swapped in by the previous owner. Everything ran great as she was for a good 6 years as a daily driver. Then I got a nicer suv as my daily and the hatch has sat pretty much un-touched since. She was parked outdoors for a few years, and garaged for the last 3 or 4. Now I got the itch to get her going again...

So she has had an erratic idle (both when cold and warm) for a couple years and I never got around to fixing it. Tried to pull the code to see what the exact issue was and realized the check engine light was removed. Popped it back in and I got a 42 (i think) it said o2 heater sensor.

So okay, order up a new o2 sensor for the d16z6, pull the old one, pop the new one in and hmm.. the harness is different. Apparently the vx 4/5-wire o2 sensor was used in the z6 swap.

From what I've read, the p28 can't read the wideband o2 sensor without rewiring it. So, my assumption is that the o2 sensor is not causing my idle issues. I'm assuming that whoever did the swap, kept the original wiring and o2 sensor, but removed the check engine light so he could sell it. I don't have emissions to deal with where I'm from so I really don't care about that. I only pulled the ecu codes to see if it would tell me where to start for the idle issue.

So my question is, will this o2 sensor cause my idle issues? It smells like it's running rich, so I thought the o2 sensor might make sense. But since it ran fine with the incorrect o2 sensor for so long, I can only assume that one of the other things must be causing this (IACV, ITIV, coolant bubble, vacuum leak). And also, should I spend the outrageous amount for the 4/5 wire o2 sensor replacement, or rewire the correct o2 for the p28?

Thanks,

mk378

Use an ordinary narrowband sensor. Rewire the harness to match it.

Trying to convert a VX to an EX involves changing a lot of stuff. You need to have an EX intake on it, that is distinguished by it NOT having an EGR valve.

d0nkey

I have an EX intake on it I believe. It may not be stock though, I'm not sure how to tell yet. The EGR valve was mounted to the firewall. The wiring was attached to it, but all of the vacuum lines were plugged off. So I removed it, unless it needs to be plugged in for some reason.

Is there anything else that I should look for as far as this VX to EX swap is concerned?

Oh and thanks for the info on rewiring the o2. That was the plan but I wanted to make sure there wasn't an easier way to get around that mess.

tony_2018

egr control valve is mounted on the firewall, egr is still on the intake.

Dump gas and put fresh gas in there, start 1st.

d0nkey

Thanks, I will try this next. Right after I take my throttle body into a machine shop to tap out the bolts that broke off trying to get to the stupid IACV and ITIV so I can put that back together and start it up.



To my original question though, am I correct that the p28 ECU cannot read the 4/5 wire o2 sensor that was left on from the VX motor during the swap?

Also, I'm reading that the z6 doesn't have an egr valve, but the VX had one and they left the control valve attached to the firewall. I'm assuming that the p28 also doesn't read anything coming from this as well.