need an idiots guide of how to change o2 sensor and clean throttle body....VN

[joeyd]

Hi guys, ive worked out i need to change o2 sensor, but i dont know where it is at all?! and i think my throttle body needs a good clean, could someone give me an idiots step by step guide to doing these two tasks. ive been looking for photos of how/ where abouts on the car is the throttle body/ o2 sensor and i cant find anything....

thankyou!

[88GreenVN]

The o2 sensor is on the left hand side back towards the fire wall on the top of the exhaust pipe/header. It will have a wire out the top and small connector. It will be tight to get undone so use a ring spanner if you can. Spray with CRC well before you attack it

[Cheap6]

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.

[Dayvo]

Or you could buy a can of throtle body cleaner and use that

[TheIceman]

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.

havent heard of that one before, only reason it should hunt and stall is if the IAC valve is not runnig as free as it should. Also, you missed a step. Base Idle!!!!
You need to set base idle when you get it all back together to make sure its set properly
I start engine with air intake off, put my finger over the IAC hole and adjust the idle speed screw to set engine speed to be just below normal idle but still idling ok. the bolt it all together and ya ready to go, shouldnt be any hunting if you have cleaned and lubed the IAC shaft ok and tested to make sure it runs freely in itself. run at 3000rpm for 10 seconds, all done.

[Cheap6]

No, do not spray carb. cleaner randomly around the TB and IAC valve gears. Carb. cleaner washes the lubrication from them. You might use some spray grease on them if the factory grease has solidified with age.

The idle can flare and hunt because the ECM has lost track of the IAC valve position. This is epecially so if battery power has been removed from the ECM and it's memory cleared or the IAC pintle pushed into the motor body during cleaning (ideally not).

There should be no need to touch the base idle speed. Unless it has been messed with before.