changed oxygen sensors, now seems to be wasting same amount of fuel if not more!

[admir87]

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Are they genuine holden oxygen sensors or aftermarket ones.I seem to have had lots of problems using aftermarket parts like Crank angle sensors etc.I will only buy original holden parts now and have not come across another faulty new part since.

yep original from holden, i never buy aftermarket

 

[admir87]

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Check your fuel pressure regulator too. Take the vacuum line off it and see if there is fuel in the line.

checked that this morning, no fuel in there. if it was gone wouldnt it cause more fuel across all injectors, not just the left hand side?

 

[Immortality]

BUTT MAJOR UPDATE,

pulled out the sparkplugs(and the left hand side ones are all black and the gap expanded very slightly,
i go to the right hand side and there all a nice white grey with proper gaps!! what the?

now keeping in mind i changed the oxygen sensors 3 days ago, what does all this mean?

could it be the old left hand oxygen sensor was stuffed, or is the new left hand one stuffed?(if so could it have fouled the plugs in 3 days!?) or could it be something else besides the o2 sensors?

btw still no error codes

check the vac lines that are hooked upto the bottom of the TB.

honestly your best bet is to get a ALDL cable and use EFIlive or similar software to check what is going on in real time


also check that the O2 sensor on the LHS is fully screwed in. i had this error as the spanner was hitting the engine block when i though the sensor was tight

 

[admir87]

anyone else have any inside on why all the passenger side would be running rich, yet the driver side is all fine

 

[Immortality]

could also be related to the O2 earthing issue that the VS models have

 

[88GreenVN]

anyone else have any inside on why all the passenger side would be running rich, yet the driver side is all fine

I'd swap the o2 sensors from side to side and see if the problem follows the sensor...

 

[pillzor]

with spraying carby cleaner down the throttle body are you doing this while the engine is running or off?
the reason i ask is i was told that it could leak down and cause some problems with something in the transmission or some ****.

 

[hako]

anyone else have any inside on why all the passenger side would be running rich, yet the driver side is all fine

Your inlet manifold gasket could be leaking on the pass side - it's not unusual for them to fail although usually they fail on the coolant side due to corrosion.
If the plugs are black, apart from indicating a rich mixture it also indicates that the plugs are not firing due to bad coils/DFI/plugs or leads. You also say the plug gap has "expanded slightly"....if the gap is much more than 1.5mm the plug cannot fire as the gap is too great for the spark to jump, so new plugs will be needed.

 

[admir87]

reply

Your inlet manifold gasket could be leaking on the pass side - it's not unusual for them to fail although usually they fail on the coolant side due to corrosion.
If the plugs are black, apart from indicating a rich mixture it also indicates that the plugs are not firing due to bad coils/DFI/plugs or leads. You also say the plug gap has "expanded slightly"....if the gap is much more than 1.5mm the plug cannot fire as the gap is too great for the spark to jump, so new plugs will be needed.

thanks hako,

how will i tell if the inlet manifold is leaking? ive got no coolant loss

i had the same thought on the coils etc, but i dont think it would be them as this means each of the coils is screwed as the pass side has 1 3 5 and these run off all 3 coils

 

[The1]

it was a known issue with the series 1, but im not 100% sure if it was fixed in series 2 models.

the way i look at it is; it doesnt cost anything to do and at least you can rule out that whilst trying to diagnose/eliminate possible causes.

It's from Series 2 onwards, when they started using heated oxygen sensors. The heater would cause a ground loop causing interence with the o2 readings, if your oxygen sensor is 4 wire you have a heater, if it's 2 wire it doesn't.

If you want to disable the heater on your o2 sensors just find the wire with 12v and cut and tape it back. The sensor will work fine without a heater it will just take longer to warm up, your o2 sensors will be heated up anyway by the time the engine starts to use them once engine reaches operating temp.