D15, D16, D17 and Mini-Me swaps
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By neo27ny
#272610 I just found out my '93 sedan lx auto has a D15Z1 and not the B7. The vtec isn't hooked up, the guy had the thermo housing plug on the vtec sensor. I put that back so now I'm down to figuring out how to wire this up. I'm pretty sure I can find the info I need for the vtec, already found a vtec harness on ebay. My concern is wiring up the O2 sensor, from what I've read I need a 5 wire wideband sensor? Anyone know where I can get one reasonable. All the ones I found are really expensive. I just need some info on the O2 sensor and possibly hooking up the EGR, I also heard this engine needs this sensor too. Thanks.
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By RWMIII
#272661 It isnt a cheap sensor. It is a wideband, thats why. Try www.sparkplugs.com , pretty decent prices.
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By teal_dx
#272698 You will need to find wiring diagrams and a pinout for the ECU. THen you can add the wires you need for the wideband and EGR valve rather than replace the entire chassis harness and engine harness. It will be much easier and cheaper to run a few wires form your ECU, through the firewall and to those sensors. :thumb:
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By teal_dx
#272699 I looked around and here's the 5 wires for the wideband o2:
A6 - heater control - orange
D14 - Sensor input - white
D16 - Sesnor ground - black
D8 - sensor input - red
ground - yellow

Actually, here's a pinout for the whole ECU:
http://technet.ff-squad.com/wiring.obd1.htm :thumb:
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By neo27ny
#272707 You are a lifesaver. I appreciate it.
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By teal_dx
#273151
neo27ny wrote:No I don't have a VX chassis. I have an LX and thought I had the D15B7 until I was looking around trying to find missing sensor plugs and realized it had vtec. I then checked the engine code and it's a D15Z1. I don't plan on building the car, it's going to be my main dd for work. I would like to get it running the way it's supposed to. I heard it gets better fuel mileage this way too. Right now it's running a P06 with no vtec. I'm assuming someone swapped the engine to a Z1 because I have an LX chassis. Why they put the Z1 in beats me unless they had another donor car. I've never come across a vx chassis before or any engines for sale so it surprised me when I saw what was in it. I was just planning on working with what I have, I don't want to drop money on a swap for a car I'm just going to be driving for work plus the d15z1 is supposed to get good fuel mileage exactly what I was looking for to drive to work.


You've kind of hit a brick wall in dealing with the auto trans. Now I'm thinking it might be easier to buy a D15b7 head and put that on your d15z1 block which would be the same as having a D15b7. Or just keep driving it as-is if it is getting decent mileage (low 30's). If you want to get into a big project and build a civic VX sedan, you'll need to do the following:
- 5 speed transmission (VX and CX both had the longest gear ratios for best MPG)
- flywheel, bolts, clutch, pilot bearing, release bearing, manual pedals, clutch line master cyl & reservoir, manual trans rear mount and passenger conversion mount, manual trans lower torque mount, shifter, linkage- the entire auto to manual swap.
- VX ecu
- EGR valve (if there isn't already one on the runners of your intake manifold)
- 5-wire o2 sensor
- wiring up of the EGR and o2 sensor
- I'm sure there's little something I'm forgetting....
All because Honda never made an automatic VX so there's no ecu. :(

They must have had a spare Z1 laying around. They should have only used the bottom end and kept the d15b7 head but maybe the timing belt snapped, taking out the valves and messing up the pistons or maybe a rod snapped, doing damage to the whole motor.

In addition to Lean Burn Mode operation of the D15z1 engine, the VX was also a lighter chassis (hatchback), had very light wheels (around 9 lbs ea.) and had a rear diffuser specific to VX hatches. So even if you sucessfully put a VX drivetrain & ecu into a lx sedan, you still wouldn't see as good of mileage as an actual VX. It might be close MPG but those little things add up when it comes to fuel economy.
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By suspendedHatch
#274209 Once again: not all VXs use the wideband O2 sensor. It depends on which ECU you have. Federal ECUs use the wideband and California VXs use the normal 4 wire O2. You have to Google the part # on your ECU to determine which it is.

It sounds like you have the original LX ECU anyway. Do not wire a wideband to your LX ECU. Only the federal VX ECU has the onboard controller for the wideband.

You also can't wire your EGR to anything but a VX ECU.