Earthing off your ecotec O2 sensors

[cxcxcxvcvcvc]

G,day lads, well been talking with another member on here (VS_pete_1) and he passed on some info on how to upgrade the earth on the o2 sensors, wich is supposed to give better economy ect, well i did it today and while i cannot vouch as yet if i will reap any gains it was not hard to do, and was not expensive! here is a list of the tools/products needed:
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Solder iron
solder
15amp wire available from repco on a roll for $5 (you will only need one roll as its 4m in length)
EYE connections also from repco about $4
electrical tape
needle nose pliers (for crimping)
side cutters (for cutting wire lol)
and if you have them a pair of wire splicers
allan key to suit top plenum cover bolts
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Ok here is the instructions sent to me from VS_Pete_1 (your a champion mate )
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Remove engine cover – 4 x 10mm nuts.

Standing along side LHF guard look down the back of the engine area to locate the o2 sensor in the engine exhaust pie. Follow wires back to the connector and unplug the connector. In the main harness side there will be 4 x wires (2 will be Black).

Without cutting wires completely (pain to repair if you do) strip back approx 5mm of insulation on the 2 black wire in the main engine harness. With a separate piece of wire – approx 400 – 500mm long (you will have to buy some unless you have some laying around at home) approx 1 to 1.5mm strip both ends approx 20mm. Twist one end of the new wire around the 2 black ones in the engine harness (the one’s you’ve just striped back) to join all 3 wires together. Solder if you’d like but at least use some electrical tape to cover. Reconnect main harness back to o2 sensor.

On the other end of the new wire crimp / solder an eye terminal (you’ll have to buy a couple with hole diameter approx 6mm (from memory the allen key bolts into the top of the plenumn cover are approx 5mm in size – double check before buying terminals).

Once terminal fitted to wire remove 1 allen key bolt from plenumn cover (the plate under the engine cover). I’d recommend a bolt closest to the o2 sensor (back rh corner when looking from the front). Fit bolt through eye terminal and retighten bolt – approx 8nm.



Carry out same repairs to drivers side and once done refit engine cover and then drive vehicle as per normal. There is no need to pull BCM fuse out to reset fuel trims etc.
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Now when it came for me to do it, i did cut the wires and resoldered them as i found it easier, but each 2 their own anyway here is some pics to help guide you along!!

[cxcxcxvcvcvc]

and the rest of the pics!

[wingwang99]

I'm not completely understanding...Did you attatch 2 wires and ground them or just the one? I'm assuming just the one, i just got confused when it said to do the same to rhs.

Let us know how economy goes...

Good write up though

[cxcxcxvcvcvc]

I'm not completely understanding...Did you attatch 2 wires and ground them or just the one? I'm assuming just the one, i just got confused when it said to do the same to rhs.

Let us know how economy goes...

Good write up though

G,day mate!
Each 02 sensor will need its own earth! so there is 2 earths one on each side of the car! if this does not make sense lol then let me know and i will take more pics
as for the economy side of things well im not sure yet but will let you know

[VrWagz1]

Theres some more info in this link, in post 2 in this thread if anyone wants to read more about them.

coolant temp sensor resistance

[B3ND3R]

there is a holden fix for this.
in the right hand bank o2 sensor, just cut the pink wire.

there is a heater element that runs at 12v constant, and is earthed at the same point as the o2 sensor which is variable depending on o2 levels. this causes interfereance and gives a false o2 reading, resulting in poor fuel economy.

the earthing described above is a bit of a myth, i have heard it from a few places but no conlucive evidence.

also, if you are doing this, you must buy 2 brand new o2 sensors.

[Tony.]

there is a holden fix for this.
in the right hand bank o2 sensor, just cut the pink wire.

there is a heater element that runs at 12v constant, and is earthed at the same point as the o2 sensor which is variable depending on o2 levels. this causes interfereance and gives a false o2 reading, resulting in poor fuel economy.

the earthing described above is a bit of a myth, i have heard it from a few places but no conlucive evidence.

also, if you are doing this, you must buy 2 brand new o2 sensors.

Are you saying that if you went to holden they would just cut that pink wire? Lol.

[immortality]

cutting the pink wire is the cheap solution. re-earthing is a better solution. i would do it at the ecu end however.

there was a thread some time ago where a test was done on a members ride with a plug in diagnostic tool before and after doing the earthing mod at the ecu. before it could be seem that the O2 readings were inacurate (outside the normal operating voltage). after the mod the O2 sensors could be clearly seen to be operating in the correct range as the AFR rolled around the stoich ratio. the member had been through a number of failed O2 sensors before hand.

[VS_Pete_1]

Hi there.
Thanks to hsvpgts (Adam) he passed this info on to me after I sent him an email.
Thanks to cxcxcxvcvcvc for adding pics and write up.

[burnsy150]

i have after market o2 sensors which have two blue and two white wires?
would i cut the wire in the actual engine wiring loom or cut the wire on the o2 sensor side of the loom (before the clip)...and as they are different colours on each side of the clip i'd cut the wire that is opposite to the pink wire on the o2 sensor loom? i.e i mean the blue wire lines up with the pink wire so id cut the blue wire

[VS_Pete_1]

vs oxygen 'pink" wire help

Read post number 6.
Engine side mate

[danja]

Presumably this only applies to heated O2 sensors? 2-wire sensors don't have this problem?

[burnsy150]

happened to of noticed any economical difference at all cxcxcxvcvcvc?

[cxcxcxvcvcvc]

happened to of noticed any economical difference at all cxcxcxvcvcvc?

nah not really @ this stage mate but my car is in need of a tune!
Although the price of fuel @ the corner bp servo is now @ less than $1 per litre so its not to bad if it drinks a bit more than usuall

[Philthy]

nah not really @ this stage mate but my car is in need of a tune!
Although the price of fuel @ the corner bp servo is now @ less than $1 per litre so its not to bad if it drinks a bit more than usuall

I would like to see you say that 5 or 6 years ago when everyone thought $1 a litre was expensive

[undar8ed1]

I'm not completely understanding...Did you attatch 2 wires and ground them or just the one? I'm assuming just the one, i just got confused when it said to do the same to rhs.

Let us know how economy goes...

Good write up though

Some ECOTECS have two O2 sensors one in each pipe, unlike VR which have
one, and that pink artificial heating wire can be cut for more economy.

[Not_An_Abba_Fan]

All ecotecs have two sensors.

[Deano87]

i have a vr with a vx v6 supercharged engine, would that sensor be causin it to dump fuel and miss fire over 3.5 grand . the guy i bought it off has done the dodgy on it, i got it wit blown heads, i thought that might have been the prob but i got brand new heads and still doin same thing.

[cxcxcxvcvcvc]

i have a vr with a vx v6 supercharged engine, would that sensor be causin it to dump fuel and miss fire over 3.5 grand . the guy i bought it off has done the dodgy on it, i got it wit blown heads, i thought that might have been the prob but i got brand new heads and still doin same thing.

could be a few things mate, faulty crank angle sensor, fuel pump on its way out, most probably though it will be the coil pack on its way out, best way to check your coils is to turn the car off and remove the first 2 leads of the first coil pack and then start the car and check that the spark from the coil pack jumps from metal tip to tip! If the spark jumps anywhere else like down or onto the coil then that coil is faulty and needs to be replaced!

[alien]

BTW, instead of stripping your wires, why dont you just use Wire taps? You can get them from any Dick Smith store cost probably like $5 for a pack of 5. Just clip onto wire, press hard with pliers and connect another wire with the adaptor to the clip you just put over the earth wire?

That's probably easier and will allow you to put the tap on anywhere (So closer to where you want to ground so you wont have to have a 40-50cm wire it can just be 10cm or less). So you'll effectivly have the original earth and another one which will help with better grounding.

[Not_An_Abba_Fan]

Any moisture you get in there will corrode the wires and the connector and lose your contact. The scotch locks are a lazy way of connecting wires that will fail eventually.

[undar8ed1]

Theres some more info in this link, in post 2 in this thread if anyone wants to read more about them.

coolant temp sensor resistance

The thing that confused me when I read that injectronics guide was that the points were from a VN-VR buick block (under the ignition module) when it clearly says VS on the top of the page took me a bit to figure it out.

[EREXON]

when you cut the pink wire. Do you simply just cut it???

and is that for both 02 sensors? i just put new sensors in but havent cut the wire yet, is it ok to do that after 2 days. Havent driven the car much.

[cxcxcxvcvcvc]

when you cut the pink wire. Do you simply just cut it???

and is that for both 02 sensors? i just put new sensors in but havent cut the wire yet, is it ok to do that after 2 days. Havent driven the car much.

Yes you just cut it and strip the wire back ect and yeah mate it has to be done on both sides! Also Not a problem to do it anytime!

[Surfwagon]

Yes you just cut it and strip the wire back ect and yeah mate it has to be done on both sides! Also Not a problem to do it anytime!

So lets get this straight for everybody.
You connect a new single black wire to the "2" black wires (all 3 soldered together) coming from each O2 sensor on each bank, as there are 2 black wires (2earths) on each sensor, LH and RH and run these 2 single wires to a good engine earth and not neccessarily together.

By the way I did the red wire cut method and logging shows that it made the O2's start working properly when cruising but they still don't read right when throttle is closed or decelerating.
Before I cut the O2 red's they were reading the same as per how they read now with throttle closed and my city usage was around the 22L/100k and highway about 14-15L/100k.
So with the reds cut my cruising/highway economy has come back to almost normal 10-10.5L/100k (used to get 9.5-10 easily) but my city usage is still hopeless up around 20's (used to get 17's easy).
Maybe my temp sensor has something to do with it.
This is driving me mad as it seemed to happen overnight because when the price of petrol fell I stopped checking my fuel usage and then when I did by chance it hit me for 6, 22.5L/100k city use.

SW