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before you go and buy a new o2 sensor, try swapping them bank to bank and see if the problem follows the sensor!!

log looks ok, nothing stands out and no faults are logged. Only thing that looks slightly off is IAC steps are a little high, should be around 30 steps usually when warmed up at idle in park. perhaps check your throttle body and IAC passage is clean and if so readjust the stop screw a little to get it around 30 steps and see if that helps.

The1 wrote:log looks ok, nothing stands out and no faults are logged. Only thing that looks slightly off is IAC steps are a little high, should be around 30 steps usually when warmed up at idle in park. perhaps check your throttle body and IAC passage is clean and if so readjust the stop screw a little to get it around 30 steps and see if that helps.

Thanks for taking a look at my log The1. No worries I'll locate the screw and clean out the TB. Mind me asking, what are IAC steps?

Holden202T wrote:before you go and buy a new o2 sensor, try swapping them bank to bank and see if the problem follows the sensor!!

Thanks for the info mate but I've already got a spare one that was bought by accident laying in the garage, probably gonna try it out this weekend and see how I go.

Thanks for the info guys.

the IAC valve is driven by a linear stepper motor, which means that it moves in small discrete steps.
The number of steps indicate how far open the valve is.

charlay86 wrote:the IAC valve is driven by a linear stepper motor, which means that it moves in small discrete steps.
The number of steps indicate how far open the valve is.

Oh I see, makes sense. I noticed this is also mentioned in the FAQ, am I right in assuming 20-30 steps is a general rule amongst all cars? Because I noticed my VY is at about 50 steps when idleing. I should probably look into adjusting that too, unless the high IAC steps are being caused by my o2 sensor.

Unless its been adjusted from factory, check/clean the throttle body and IAC before making any adjustments to the stop screw.

also keep in mind, things like fans or A/C will increase the IAC steps (so as to keep the same idle rpm) so if you want to set it make sure the engine is at running temp with all accessories like a/c turned off.

No worries I'll give the TB and IAC a clean before adjusting anything, and I'll keep all accessories turned off when monitoring it. Holden202T, by fans do you mean the radiator fan too? Mine seems to run a few seconds after I turn on the VY with the ALDL cable plugged in, I'm assuming this is because of the fan communication being disrupted by the data connection, and IIRC these radiator fans will turn on three seconds after turning the car on or starting it if the temp. sensor is not communicating with the PCM (e.g. unplugged/not working).

Could prove a little difficult to tweak the IAC steps if the radiator fan increases them while I monitor it if that is the case.

yeah thermo fans is what im referring to, know if you have the A/C on this will usually request the fan on etc so just turn as much off as you can.

i think for a commodore v6 the fan on IAC step increase is only like 7 steps or something, its just all stuff you need to take into consideration so you don't set the IAC warm idle steps too high or low.

Right so I've gotta adjust it till the IAC steps shown on my VY is about 37 to make up for the 7 steps that the thermo fan creates?

Thanks for the info.