# HELP! O2 sensor wiring diagram!



## rub-a-vee-dub (Sep 29, 2001)

so i called that guy at Casper's, someone posted the link the other day, and he's not sure if he's got something to fool the post-cat O2 sensor. he asked for a wiring diagram, checked my Bentley, not in there.... does anyone know? please, help, he may have something so we can run catless


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## rub-a-vee-dub (Sep 29, 2001)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*

for the love of god i know someone out there has to know this.... for the good of us all so that we may run catless and CELless, please, help.


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## Shaka (May 20, 2001)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*

All i can say is the black is the signal wire on the downstream.. hope that helps ya..


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## rub-a-vee-dub (Sep 29, 2001)

*Re: HELP! O2 sensor wiring diagram! (Shaka)*

well that's more help than anyone's given, thank you. 
i don't understand how a site filled with so much intelligence, and no one can answer this? someone out there has to know... can someone tell me at least what colors the wires are (besides the black, thanks again Shaka), and how many wires there are?


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## rub-a-vee-dub (Sep 29, 2001)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*

ok... how about this, does anyone happen to know how or where i could get my hands on an O2 sensor to send to this guy?


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## adityaax (Jun 18, 2001)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*

Umm...the dealer?


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## dangonay (Dec 31, 2001)

*Re: HELP! O2 sensor wiring diagram! (adityaax)*

OK, here's what I have on my DVD:
Red/Grn wires are common to both O2 sensors, they are for the heater, +12V when ignition is on.
Red/Wht is the other heater wire for sensor #1.
Red/Yel is the other heater wire for sensor #2.
Gry & Blu wires are the 2 sensor wires for #1.
Vio & Red wires are the 2 sensor wires for #2.
These wire codes are for the connector that plugs into the O2 sensor itself.
The wiring colors for the sensors itself are:
Wht & Wht are the heater wires.
Grn & Blk/Wht are the 2 sensor wires for #1.
Gry & Blk/Wht are the 2 sensors wires for #2.
Hope that helps.


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## rub-a-vee-dub (Sep 29, 2001)

*Re: HELP! O2 sensor wiring diagram! (dangonay)*

awesome.... thank you so much.
so that's 4 wires on the sensor? 2 whites, a gray and a black/white?


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## Staley (Mar 6, 1999)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*

Question.
Are you trying to come up with something to fool the ECU.. because you took off the catalyst and you do not want to set the Catalyst efficiency P0420 OBDII code??? If that is the case.. the ECU watches the rear O2 sensor during steady cruise.. if the rear after cat O2 sensor switches rich..lean then it sets the code.. The only reason for the rear sensor is for the catalyst.. and a lean cruise condition.. The ECU wants to see a constant lean on the rear sensor(during cruise and steady throttle).. meaning the catalyst is working.. so on O2 sensor land.. 0mv generated is lean and .9v generated is rich.. 
here is an idea.. don't know if it will work but it is worth a shot.
Leave the sensor plugged in.. because if you unplug it you will also set a sensor heater code...
snip the sensor wire(on the sensor.. not the vehicle harness) and ground it. This will always send a 0 voltage to the computer and the heater will always show working. and this might keep your light off.
-mike


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## AxeAngel (Mar 28, 2001)

*Re: HELP! O2 sensor wiring diagram! (Staley)*

um...
aww and awd have different wires...
awd you snip the black wire as that is the signal wire and get ur a/f from there.


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## rub-a-vee-dub (Sep 29, 2001)

*Re: HELP! O2 sensor wiring diagram! (AxeAngel)*

quote:[HR][/HR]um...
aww and awd have different wires...
awd you snip the black wire as that is the signal wire and get ur a/f from there.[HR][/HR]​well... you seem to know what's going on.
do you know which wire does what for an AWW? i'm trying to see if this guy can make an O2 simulator for our cars, so we can run catless. does that grounding trick work? which wire would you ground from an AWW O2 sensor?


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## O2VW1.8T (Jul 9, 2003)

*Re: HELP! O2 sensor wiring diagram! (rub-a-vee-dub)*


_Quote, originally posted by *rub-a-vee-dub* »_<BLOCKQUOTE>quote:<HR>um...
aww and awd have different wires...
awd you snip the black wire as that is the signal wire and get ur a/f from there.<HR></BLOCKQUOTE>
well... you seem to know what's going on.
do you know which wire does what for an AWW? i'm trying to see if this guy can make an O2 simulator for our cars, so we can run catless. does that grounding trick work? which wire would you ground from an AWW O2 sensor?


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## enginerd (Dec 15, 2001)

*Re: HELP! O2 sensor wiring diagram! (O2VW1.8T)*

I believe that the motronic is supposed to look for transients as well as actual O2 readings. I beleive this casper part was tested a couple years ago with no good results. Try the other thread with the mechanical fixes. may be a better way to go.


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## Dave Brabant (Sep 4, 2017)

Sorry to revive this thread I've changed my o2 sensor and my cat yet I still get o2 1 code precat... So I'm assuming it's my wiring that's faulty does anyone know if there is a connector in the engine bay leading to the o2 or where the wiring comes out up there so I can check it?


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## NathanCarini (Oct 11, 2020)

Dave Brabant said:


> Sorry to revive this thread I've changed my o2 sensor and my cat yet I still get o2 1 code precat... So I'm assuming it's my wiring that's faulty does anyone know if there is a connector in the engine bay leading to the o2 or where the wiring comes out up there so I can check it?


HOPEFULLY THIS HELPS I am currently in a issue where my front o2 sensor continues to throw a signal lost intermittent code p0134 I think was it and replaced my o2 and ecu still the code is there also have used the old o2 sensor on my dads car runs perfectly fine no codes so I’m almost positive it’s a wiring issue going to be rebuilding it soon with new wires and plug to o2


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