I'm not 100% sure it's worth it, but with these little engines, I'm sure every little bit helps. It was $40 from a local junkyard, so I figured I'd give it a try.
How I got mine to work.....
-Melted adhesive on adjustment screw.
- Installed WITHOUT adjusting at idle for 20 mins while it went through looking at and trying to learn the new throttle body.
-After it fluctuated for 20 mins. I adjusted the screw 2.5 turns counter-clockwise (I think). Then restarted and let it go through procedure again until the idle calmed down.
-Another guy in the iQ group after I did it, did it also, but it took more turns for him for whatever reason, but it eventually learned adjusting 1/2 turn each time, and then letting it sit to relearn idle.
Mine works 95% fine most of the time unless it's very hot and humid out at which point it fluctuates up on a cold engine start to about 2-3k rpms, and then immediately back down in under a count of 5. Then no further problems.
Do I think it was worth it? Yes for the cost, most definitely. If you prefer not to go that route, you can also send your throttle body to
http://maxbore.com/ who can port, polish, and add a new throttle plate.
Another friend of mine also has access to a guy making throttle body spacers for the 1NR-FE throttle body if you're interested I can get his info.