mjshealy

hey all, i have a 94 civic vx that had the d16z1. It was swapped out for a z6 with a p28, never could get an o2 to work. Now, it has a Vtec SOHC ZC (basically the same as a USDM Z6, ZC block with d15b head). The ZC motor takes a 1-wire o2, as i am running the native p70 ecu with the zc. A while ago, i cut out the entire o2 harness from the firewall to the motor because i was so pissed it woudnt work. i spent days ohming, testing and it would never work with an o2 sensor. My question is this: since i have a 1-wire o2 now, what wire do i need to run straight from the ecu to the sensor? does it HAVE to be shielded? is the shield grounded? and the most important part, anyone know which ecu pin it is for the 1- wire (the 92 - 95 civic cx also utilizes a 1-wire o2). Thanks for any help in advance, i truly appreciate it. it's getting cold here in VA now, and the car's doing some spitting and sputtering

Skunk2Joe

chip the ecu and turn the o2 sensors off

BryanM.

iTrader: (1)

http://www.ff-squad.com/technet/wiring.obd1.htm

mjshealy

thank you mcvtec. I do not plan on and i will not chip the ecu. Too many problems arise from it, you can blow your motor, and it doesn't help the problem... it just turns off the sensor, turning off the code for it. It'll still have the same issues so why bother?

As an update, i bought a new bosch sensor for a 1-wire civic cx and a roll of 18 gauge primary wire and wired the new o2 straight to d14 on the ecu, and it's STILL pulling code 1- Primary heated o2. As i understand, 1-wire o2's aren't heated so the cx ECU and the p70 ecu aren't supposed to pull that code. This is the second ECU that this has arisen from, so i know it's not the ecu. It's got to be something in the wiring, but idk what. any suggestions?

BryanM.

iTrader: (1)

Yes single wire 02 sensors do not have a heater circuit.

Code 41 is specifically Primary 02 Sensor Heater circuit failure/improper signal, where as Code 1 is a general "something is not quite right with the 02 sensor" kind of deal.
Basically the P70 ECU is saying it's not getting a satisfactory signal or not getting any signal from the 02 sensor.

Definitely try running a wire from the 02 sensor directly to D14.

I do not know if that wire needs to be shielded, but I doubt it. Maybe someone else can give you some insight on that subject.

mjshealy

Yea, i did run the wire straight to the o2 from d14, it still doesnt work. I even found a service manual... The o2 is showing over .6 volts at WOT, and right below .4 volts at a quick release of the throttle. So that means the o2 sensor is fine, which i knew because it's a brand new bosch and i've bought 3 sensors so far trying to get this thing working right. btw, does anyone know where i can buy JDM ecus? that's my next step, but i cant find a P70 at an average price anywhere.