To address the Q in another post: the connector is part of the (new) O2 sensor.
The throttle body (TB) is on the back of the engine at the top. There is a "How To" on cleaning it.
Basically:
Disconnect the battery earth lead - black. You don't have to do this, especiallly if you have a coded radio without the knowing the code, but it minimises the risk of problems.
Undo the 10mm head bolts that holds the cable bracket onto the TB or unclip the two or three cables from the throttle body. These are the TV cable for the auto, the cable for the accelerator and possibly a cable for cruise control. The TV cable slides off and is easy to break if you are rough with it. Likewise, the retaining clip for the CC is easy to lose.
Forgot: you can buy the O2 sensors from pretty much any auto. parts store or an franchised Holden dealer.
Remove the inlet air duct from the air cleaner. It's easiest to undo the hose clamp at only the TB end and unclip the air cleaner housing upper. Don't miss the 10mm head bolt on the support for the duct (probably broken already but...).
Unclip the electrical connectors - two; those for the throttle position sensor (TPS) and for the idle air control valve (IAC) motor.
Remove the two vacuum hoses to the Carbon canister, the short 'S' shaped hose (PCV hose) between the inlet manifold and the TB and the hose at the back for the manifold pressure (MAP) sensor.
Undo the two 13mm head nuts that hold the TB onto inlet manifold - without dropping them - and remove the TB. There is a gasket between the TB and the inlet manifold elbow which can be reused a couple of times if you are careful not to damage it. It may be worth buying a new gasket before you start.
Remove the two torx head screws that hold the IAC motor onto the TB. You can use a small flat blade screw driver instead of a torx bit if you are careful as the screws should not be very tight.
With a cloth soaked in kerosene, not carburettor cleaner cleaner, carefully wipe the oily build up from the end (pintle) of the IAC valve, the edges of the throttle plate and the TB bore, and the IAC valve seat. You can use a little bit of carb. cleaner to clean out the ports in the TB but avoid allowing carb cleaner to flow into the bushes or bearings for the throttle plate.
Then put everything back together. You should put a little bit of engine oil on the 'O' ring on the IAC valve motor body before refitting it. Replacing that 'O' ring is probably sensible also.
When you first start the car the idle will probably hunt around some. Simply wait until the engine warms up and then allow the car to idle in drive and neutral (auto.) with the A/C off and then on. You can just drive the car but be prepared for it to stall or the idle speed to flare until the ECM relearns the positions of the IAC valve.
