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Code 64 - LH Oxygen Sensor Lean (O2)

zac_sa

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On my VS, Ive been having issues with it running rough and stalling.
On checking the codes I originally got a Code 47 (CAS)
I replaced the CAS (which was a bitch to do unfortunately) and to my amazement the orange light came on again as soon as I drove the car again.
The car is still running rough but touch wood, even in the heat it hasnt stalled although ive been concerned it will.
Its almost like at idle it needs to be 100-200 RPMs higher and sometimes on take off theres lag with any accelaration.

I re-checked the error codes and im now getting Code 64, O2 sensor lean.
The other thing I should mention is my fuel economy is shitful, around 18litres/100km (city driving)
I know the sensors can become faulty but with the way the engine is running its obviously an issue.
I checked for vacuum hoses etc and all seems intact.
Ive always had a crack in my manifold so thats not the problem and when it gets hot it expands so theres no leakage of gases there.

Any suggestions?
 

Vee-ard

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Seems pretty straightforward...

Replace the oxygen sensor? its obviously telling the ECU its running lean so the ECU gives it more fuel, which is why you're getting 18L/100Kms..

My guess anyway.
 

zac_sa

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I wondered about that, This may sound silly, how do I disable it temporarily so as to check if it fixes the issues.
ie without cutting the pink wire.
 

Brett_jjj

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I wondered about that, This may sound silly, how do I disable it temporarily so as to check if it fixes the issues.
ie without cutting the pink wire.

Cutting the pink wire wont disable the 02 sensor.It will just stuff up the 02 sensors heater,which will probably make it even worse than it is now.As said above,the 02 sensor needs to be replaced.Too easy mate.Id do both at the same time so their readings are similar.
 

Not_An_Abba_Fan

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Cutting the pink wire is actually Holdens fix for the RH sensor giving incorrect feedback to the PCM.

Running rough and lean could possibly be a vacuum leak.
 

RX25SE

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I would replace both O2 sensors and rewire the earths.

Mine had a really odd graph for the LH sensor so I replaced both. Still had a crappy graph, so i rewired the earths and the graph is OK now.
Still had a slow/poor idle (fuel consumption was OK) so I cleaned the mounts for the DFI (poor earth) and all is good.

Runs smooth.


Well, as smooth as VS can get anyway! :)
 

Brett_jjj

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Ive also found when doing memcal tunes, that if a VS was released with the BSTK memcal version,and you try to run one of the newer versions of the VS memcal,Like BWPJ or BWXP ,it will give bad 02 sensor readings and can also set error codes 76 and 78.Ive even tested it with the modified 02 sensor earths,and its made no difference.I wonder how many people have fitted a later memcal version and have had trouble like Ive described.At first I thought its just a problem with my car,but then Ive talked to a couple of other people who have ran into the same problem with their VS's too..The BSTK memcal version was replaced by holden for the BTXP version because of pinging and cold hesitation problems.Ive asked a few people in the know about it,and no one can say why this happens.So for the time being ,Im stuck using the older version of the VS memcal,Id like to be running an updated version as they run better,but cant because of this problem.Anyway,if you have a VSV6,its worth checking what version of the memcal is used if you are swapping over memcals like when buying a tune.Find out what version was used as the base for the tune.The version is written on the memcal itself under the blue cover,and also on the ECU sticker.Its also worth checking this out if you have bad 02 sensor readings,and cant find out whats causing it.
 
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zac_sa

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Ive just changed over my o2 sensors and by that I mean i swapped left over to right and vice versa. The left hand one (the one indicating the error) was black in colour and the other was white.
I went for a test drive for a few k's and the engine light didnt come on. The fuel economy changed from 18L/100km to 15L. I checked the error codes after the test drive. (they were reset before test drive) and im not getting any new error codes.
I'll have to wait till I drive it longer for an error code to log. Hopefully it now is the right hand side indicating as lean then I'll know its definitely the sensor and I'll replace them.
 

PRAVX II S

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It is easy to test the Oxygen sensor.
When the car is started(cold) it operated in open loop mode supplying more fuel. until the oxygen sensor heats up then it will operate in closed loop mode.
The oxygen sensor need to be at least 300 degrees to operate. They have a internal heater to get them up and running.
Any way the way to test the sensor is to get a multimeter and put it in VOLTS (milli volts) mode dont put it in OHMs mode because you can damage parts.
The voltage should be reading low and high continually changing.
Rich higher voltage lean lower voltage.
I think it ranges from as high as 800mv-and as low as 200mv. Have not done one for ages
 

zac_sa

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