Gtr O2 Sensor Id & Wiring?

[STAGTR]

G'day all,

I have an oxy sensor problem on my RB26... I have searched extensively, but can't find the right info.

I recently bought a stag w/ an RB26 conversion... however, when I plugged in the hand controller (Using R33 GTR D-Jetro Power FC), I saw some funky stuff going on with the O2 sensor readings.

O2-1 (Front sensor) always reading around 078-0.82V (which is rich on the Zirconia 0-1V scale)

O2-2 (Rear) gave me readings of around 2.2V?! (if this is a WB or Titania 0-5V sensor this would give a nice ~14.4 AFR)

The rear sensor looked dodgy, so I checked it out and it was wired differently to the front sensor? (Bugger)

I ran a quick resistance check over the two O2 sensors to see if they were in spec and got 6-7 ohms... all good there.

I thought it might be a mis-wire at the ECU end on one of the plugs... I traced back the loom connector wires to the ECU with the following:

Pin 55: Clear sheath -> Signal input into ECU from sensor (front)

Pin 29: Clear sheath -> Signal input into ECU from sensor (rear)

Pin 115: Brown w/ white stripe -> Exhaust gas sensor ground (common?)

Blue w/ white stripe -> supplies +12V but has no dedicated ECU pinout (AFAIK)

Here's a photo of what was connected when I bought it (the full connectors were on but I have removed them for easier testing/troubleshooting)

Now both my O2 sensors have 3 different colour wires... Red, Black and White and look remarkably like an OEM R32 GT-R oxy sensor, (see link) http://www.kudosmotorsports.com/catalog/po...age.php?pID=184. Pretty much everything else I have read only talks about 2x white and 1x black wire, with the black being the signal wire.

I did a wider search on the net and all literature points towards the black wire being the signal wire on the sensor as an alternative for Nissan oxy sensors... but when I do a resistance check I get a circuit across the Red and Black wires -> this would indicate that the White wire is actually the oxy sensor signal wire.

I have tried wiring the O2 sensors 2 different ways with completely different results:

1. Black = signal

Red = Blue & wt stripe (+12V)

White = Brown & wt stripe (O2 sensor grd)

This gave me readings around the 2.2V mark, kinda like you would expect to see on a titania 0-5V sensor... however it ran pretty rough.

2. White = Signal

Red = Brown & wt

Black = Blue & wt

This gave me readings around 0.52V, which would be pretty good on a Zirconia sensor... but still ran rough. Not surprising I guess considering the tune was for a mixed bag of O2 sensor readings (maybe some sort of limp home mode?)

Does anyone know if my O2 Sensors are Genuine Nissan R32 GT-R's?

If so, what is the wiring breakdown for these sensors?

Is it a Zirconiz (0-1V) sensor or a Titania (0-5V) sensor?

Why the Fark was it tuned with O2 sensor readings so wrong in the first place? (don't have to answer that one!)

Which reading should I be supposed to get... (pretty sure it should be as in 2. with around 0-1V)?

How safe is it to now correct the wiring messup and drive around on that current tune with only the O2 sensor input changing? I know this can be subjective and depends on the maps etc... but if I run the O2 sensors in feedback mode with no boosting, shouldn't the ECU correct injector duty cycle to ensure the target AFR is achieved??

It was a good tune in spite of the O2 sensors being wired wrong AND Injector capacity correction wrong (73% nstead of 55%) AND injector latency calibrated wrong ()ms instead of 33ms)... made 345AWKw's (saw it myself on the dyno... with solid 12 ish AFR's all the way through boost)

Lots of questions, would appreciate any words of wisdom.

Cheers

Edited December 16, 2008 by STAGTR