Community Member Credit: Frank / motorvate.ca
I have found that I need to clean my throttle body about every 30,000 KM. If I don’t my idle will sometimes fall to below 500 RPM, and the motor catches itself and revs up to 1,000 RPM to then fall back to about 750 RPM. If it is very dirty it stalls. I also noticed my 1st gear launches become very jerky.
You may also notice a loss in lower RPM torque. If the throttle body is very dirty, the idle speed control valve (ISC) can not allow additional air to bypass the butterfly plate in the throttle body. The is the reason for the jumpy idle noted above, as well as a loss in low RPM (1,000 to 3,000 RPM) torque. The ISC has a strong influence on the air/fuel mixture up until about 3,500 RPM.
When you clean the throttle body and butterfly plate, you allow the ISC to do its job. This is not very hard to do, with the cost being about $8 for a tin of “Combustion Chamber Cleaner”
Ihave a Stillen Cone filter from my NX-2000. I was able to drill and tap 3 more holes to reuse it. It fits perfect. Anyways, disconnect the ACT (air charge temperature) sensor shown by white arrow.
Remove the air filter, and disconnect the MAF (mass air flow) sensor.
Remove the clamp as indicated by the white arrow. As shown in the picture, slide it up hose so you don’t forget about it or loose it. Right:
Remove the small black rubber hose as shown by the white arrow. The yellow arrow points the to disconnected rubber hose.
Remove the clamp as indicated by the white arrow, and slide it to where the yellow arrow is for safe keeping. Right:
Loosen the worm gear clamp on the throttle body.
Remove the bolt as shown by the white arrow. Right:
It may take a little work, but now you can remove the oil separator / MAF as one unit.
Now you can see that we have very good access to the throttle body. Right: 
Here is a view inside the MAF. The smaller circle in the middle hold the “hot wire” to determine actual air flow.
We have removed the air filter, MAF, and the oil separator. (the big black box) We now have easy access to the throttle body and butterfly plate. Time to clean!
The gray arrow shows the build up of dirt and oil. (No, it is not a shadow) Right:
Here is what I use. It is available at Canadian Tire.
With the throttle wide open, spray the cleaner in, and wipe with a clean white rag. Make sure to remove any dirt and oil from the EDGE of the butterfly plate. The white rag allows you to see how much dirt and oil you have removed, and when the throttle body wipes clean, and the rag stays white, you are done. Right:
I like to use an old tooth brush to clean the throttle body. I hold the throttle wide open, spray in the cleaner, and scrub the throttle body with my tooth brush. (as seen resting on the throttle body) You won’t believe the dirt and oil in there!
Here is the clean throttle body and butterfly plate. Right:
This is the dirt and oil removed. This rag was new.
From here, just follow the opposite if disassembly. Make sure not to over tighten anything. A common belief is that it is better to have it a little too tight, than too loose. From what I have seen, when bolts (especially small 10 mm bolts) are over tightened they strech and are very difficult to remove the next time. My rule of thumb is snug plus 1/4 turn for the small bolts.
Summary
When the car is put back together again, you should notice your idle being more stable, and maybe improved low RPM torque. I know I did, but my throttle body was quite dirty.
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