killerb7888

I put a D15Z1 in my 90 CRX and have not been able to get it running right. It was throwing a code for the o2 sensor and since this motor has the 5 wire o2 sensor no company makes a direct plug in ECU adapter so I had to work with what I had. I found what I thought was a good diagram on google for the ECU pin layout and re-wired my harness and added a few additional wires for the extras on the o2 sensor and tried that but now my CEL is solid and will not flash codes.

Long story short, I'm giving up. I don't have time to fuss with this, I'd rather just pay a shop to do it right one time and be done with it. The shop I've talked to says that it will be much easier to just use a wide band o2 sensor and tune the ECU to work with that. I've stressed to them this motor is for fuel economy, not speed and they still say that is the best route. And they also say they will bypass the EGR valve when they do the tune.

My questions are...

1) will a wide band o2 with a proper tune really get me the same fuel economy that my stock 5 wire one will?

2) will bypassing the EGR system hurt my motor or fuel economy?

3) where can I buy a wide band o2 sensor? They guy is going to charge me $240 for the sensor and installation and I have the tools to do this in my garage.

HondaPartsHero

The Denso one is $155 from rockauto.com

DENSO Part # 2345052
OE Style; 5 WIRE
Upstream; VX Model; D15Z1 Engine; Except California Emissions; OE Quality Replacement Sensor $155.79

killerb7888

The shop is suggesting I use a wideband o2 sensor, not a stock replacement.

Robert2011

One year ago, I took the wasted D15B7 out od my 93 Del Sol and put in a D15Z1. I had the same problem you are having. What I did (right or wrong) is I took all the components out of my B7 distributor and put them into the Z1 distributor. Everything plugs in and I didn't have to buy a new computer or O2 sensor.

aaronhume

I know I am digging this up, but I thought I would throw a little info out here...

I did a D15Z1 (JDM D15B) swap into my 94 civic and for a long time had a code for the LAF/O2 sensor, and replacing the sensor with a OEM replacement (~$155) that fixed the code.

regarding the distributor, I am pretty sure (could be mistaken) that the Z1 distributor is the same as the D16Z6/Si motor (and spark plug wires).

However, this comes with some assumptions:
Are you using an OBD1 ECU for the 49-state VX engine? (P07 ECU)
did you convert your wiring to work with an OBD1 Engine? (ECU, Distributor, O2, Vtec stuff, fuel injecotrs, etc.)

For the ECU, you can also look into using a california VX ecu and run a standard 4-wire o2 sensor. the reason they did not allow the wideband in CA is because the emissions were just a little too high in lean burn mode. You can also convert a P06 ECU to run Vtec and run a CA P07 fuel map to get decent mileage, but no lean burn at all.

check out my thread about my VX engine swap if you want some more food for thought (in my signature)

OptimisticWay

I have the JDM equivalent of a D15Z1 and recently swapped the distributor into my EJ1 95 Civic EX D16Z6 and it works fine. It is the same distributor and same part number. You can confirm this on Majestic Honda's website.

What ECU are you running? What transmission? What vehicle speed sensor (VSS)?

You need the O2 sensor that came with the engine in order to get lean burn and get 50 mpg. You also need the entire feedback system which includes the EGR otherwise your fuel economy will suffer. Don't let these guys talk you into this.

OptimisticWay

http://www.crxmpg.com/crx-d15z1-civi...my-swap-guide/

All the above information can be found at this website. I hope this helps you finish your project and achieve your goal of great fuel economy. I too am a fan of the D15Z1 and the D15Z7 3 Stage Dual Vtec engine.