How To: Fix the VS V6 4 Wire O2 sensor earth problem – Known Holden Problem

[ephect]

Yea it is a bit much, should average between 8-11L/100km

Have u tried swapping the u2 sensors around? Have u checked the memcal version as Bret_jjj suggested? U need to read what is posted and answer so we can help u out.

Might be any number of things, u'll get more of a response if u post up a new thread with all ur info in it, this is mainly for any issues or feedback related in doing the o2 fix.

[altaaf]

hey,

i have tried both BTXP and BSTK but the car came stock with a BSTK i have put in 2 new sets of o2 sensor all up 4 but still didn't make a difference and i have swapped it around as well. i have put back the the old original o2 sensor back and the readings are normal now, but i have ordered a new set again this will be my 3rd set all up lol...
and also i forgot to mention mine is a BT1 version ute...
it is a vs v6 1999 model...

hey guys thanks for your help really appreciate it
cheers

[duca1991]

Hey guys,

I just tried the Fix at the ECU, but instead of splicing into the black wires, i just cut them and re earthed it onto the chassis.
I figured because they are only earths into the ECU it wouldnt hurt just to do a proper job instead of splicing into wires.

Just wanting to know if this affects the o2 sensors by cutting the grounds from the ecu?
Do they need to be earthed to the ECU for proper readings or?
It's got me thinking.

Thanks

[ephect]

Umm, this I do not recommend.. But I need a little more info. Did u ground both, ecu wire and o2 wire that u cut?

I know u can earth them in the bay, but I believe it's still connected directly to the ecu. I can't guarantee the end results. I guess in theory it still should work, but I would be leaving a direct wire to the ecu.

[duca1991]

Thanks for the reply,

I copied exactly what you did in the first post in this thread, followed the photos you uploaded, but where you stripped the wires, i cut and twisted all 3 D14 d16 and a2 together and did the ground onto the chassis just under where the ECU sits.

The other end of the D16 D14 and A2 wires that i cut just comes out of the ecu are just hanging and i put electrical tape around the ends.
Just thought they are grounds into the ECU, thought maybe the ECU had a ground circuit inside from the engine bay somewhere.

I havnt touched the actual power wires to the sensors that come out of the ECU, i only tampared with the 3 black Wires you said .

Thanks.

[ephect]

Thanks for the reply,

I copied exactly what you did in the first post in this thread, followed the photos you uploaded, but where you stripped the wires, i cut and twisted all 3 D14 d16 and a2 together and did the ground onto the chassis just under where the ECU sits.

Is this end wires from the ecu? If so, u've grounded the only the ecu, which doesn't then feed to the actual sensors, which is how this fix works.

The other end of the D16 D14 and A2 wires that i cut just comes out of the ecu are just hanging and i put electrical tape around the ends.
Just thought they are grounds into the ECU, thought maybe the ECU had a ground circuit inside from the engine bay somewhere.

Is these are the wires in the loom, the feed back to/from the sensor, these need to be connected foe the sensor to work

[duca1991]

Hmm

Yeah, the black wires that come 'OUT' of the ecu and go to the sensor are cut and i have just grounded it to the chassis.
Although the power wires from the ECU are still connected to the sensor if you know what i mean.

So it goes, power from ECU to sensor then back from sensor to Chassis ground. instead of going back to the ECU.

Thats wierd, didnt think they would do anything other than ground.
What does the black wires from the 'sensor' into the ECU actually do?

Ill have to resolder those wires together then splice into another section and redo the fix.

far out =[

[ephect]

The black wires that go to the sensor, complete the o2 sensor circuit. u've grounded the ecu but in turn have disconnected the circuit.
If anything, join the 2 wires that are taped, and ground them to the same spot, SHOULD do the same thing.

This is the reason how-to's are written all the hard work of thinking has been removed, and it should be easy to follow the steps.

[duca1991]

Thanks again mate,

Ill just take the tape off and connect the loose wires out of the ecu to ground wiring i have already done.
Sorry to have annoy you lol.

take care,

[ephect]

Lol u haven't annoyed me. It took a bit of time to write up the guide to make it easy for all to understand. And trust me, I hate doing things the long way, it's a little involved but it works.

Do it right, do it once

[duca1991]

So true,
very well written up to be honest.
I had actually followed your diagram step by step my first shot and went through a tank and it didnt seem to help, like the other person had alot of trouble with his 99 VS ute. I myself have a 95 VS sedan.
I saw somthing about a memcal problem with the 95 vs's earlier on in the thread, but im pretty sure my memcal has its original stock one.

Just a quick question, since i have cut the black wires that go back into the ECU from the sensors would i be getting an error code? it would be a strong reading. the o2 sensors are obveously not working lol. Because i had the car running for a few minutes after they were cut and i still got the 12 ok code.

Can i have your opinion on that?

[ephect]

generally, the o2 sensors have to heat up enough first, thus telling the ecu its ready and to drop out of open loop. it then feeds readings to it, only if no readings or over voltage readings occur, this is when it will log a code.

you've disconnected the heater (from memory maybe the o2 curcuit also), so it takes longer to heat up, in turn longer time in open loop, using more fuel. i dont believe you've run the engine long enough for it to log anything.

redo the fix as ur first go at it, disconnected the battery for a couple mins to reset the learnt process of the ecu, replace ur o2's if you havent already. then drive around as normal for 2tanks so the ecu will learn again. hopefully at this stage consumption should start to drop. if not this hasnt been the cause of your increased usage.

hope that makes sense

[delcowizzid]

earth direct to the engine as per factory or the ecu will see variances in the voltages

[Remdogg]

Thanks for the info. I had error code 63 No signal LH oxygen sensor. Did this and new sensors then cleared the fault codes with my mates G scan unit and drove around with it plugged in and it said I was getting 7.9L/100Kms when cruising. Couldn't be happier.

[ephect]

thanks for the feedback, its always good to hear of another success story

[aussie4life11]

well ive had a similar problem in my 94 vr v6. can i just earth the o2 sensor straight off it to the chassis or not?

[ephect]

im not 100% sure that this affects the VR!

you can, u'll have to splice into the earth wire and find a bolt on the body.

[Excale]

My 94 VR manual has started to be really shit on fuel. The engine light will come on while driving then turn off for awhile and come back on! just did a diagnostic test and got Code 13 - Oxygen Sensor (O2) - No Signal . do i have to re-earth my ecu like you and buy a new o2 sensor?
cheers

[ephect]

For starters, the code 13, is saying no signal, meaning the o2 is screwed. Being a vr, I don't believe this fix applies.

I would change ur o2 sensors, reset the ecu (dc battery) and then Go for a drive long enough for the o2 to heat up and work correctly. Then check again for any codes, which ther shouldnt be any.

Ur issue I believe is a simple replace o2's and away u go. Results will tell!

[Excale]

For starters, the code 13, is saying no signal, meaning the o2 is screwed. Being a vr, I don't believe this fix applies.

I would change ur o2 sensors, reset the ecu (dc battery) and then Go for a drive long enough for the o2 to heat up and work correctly. Then check again for any codes, which ther shouldnt be any.

Ur issue I believe is a simple replace o2's and away u go. Results will tell!

Thats what i expected! Buying a new o2 Sensor tomorrow and will let you know how i go, cheers for the response.

EDIT: Bought the o2 sensor and installed it and all seems good! cars running alot better, i filled the tank to full so i'll monitor the fuel consumption. Cheers