Well, i got tired of my RPM's dropping to 500 or so and headlights dimming when at idle. I kept noticing on my A/F gauge that I was running pretty rich at idle, and decided to clean all the gunk that had built up in the TB and butterfly. Here's a how-to for the 4G69 guys, but you 4G94 guys can use this as a general guide. Tools Needed: 12MM socket and ratchet 4" extension TB cleaner (not TB and carb cleaner...Mitsu's tend to not like the carby cleaners that much) Clean rags Start off by removing whatever intake you have to gain access to the TB. I had to remove the injector cover also to have plenty of space to work. Next, remove the coolant hoses that run in and out of the TB. (not sure if you 2.0 guys TB's have these) nThere is one under the intake side of the TB and one on the rear. The rear can be a little tough due to small work space, but be patient. After you take the coolant hoses off, remove the ISC motor connection to the left of the TB. The 2.0 has the accelerator cables on the firewall side of the TB. Remove the four 12MM bolts connecting the TB to the intake manifold. Be sure to take care of the gasket between the TB and mani, unless you have a replacement. When the four bolts are out, you can now fully remove the TB from the engine bay. You can see that it has been a while since I last cleaned it, so there was quite a bit of oil sludge built up on the backside of the butterfly and just inside the mani. (note the dark ring next to the TB butterfly) Now, just go to town with the TB cleaner. Spray a decent amount inside the TB and let it penetrate for a few seconds, and the pressure from the can should knock off most of the buildup. For the tough spots, spray some cleaner on your rag and clean the top and bottom edges of the butterfly, and the sludge still on the TB. Keep in mind to also clean the mounting points to ensure a good gasket seal after re-install. When you are satisfied with the results...take a break and make sure the majority of the cleaner evaporates out of the mani and TB. You may not get all of the dark spots off the butterfly...it does stain a little. If you are re-using the gasket, inspect it for cracks or bends that could cause a leak. I put the top bolts through the TB and then hung the gasket on the bolts to make it easier to get lined up correctly. Now it's just a game of reversing the steps to re-install. After the bolts have been tightened, just put the coolant lines and IAC connection back on (throttle cables for the 2.0) and throw the intake back on. If you had a good bit of build up, do the normal procedure of letting the car idle for 10-15 minutes...just to be safe. Go for a drive, and check for anything out of the ordinary. I had a decent amount of gunk, so I had a noticeable increase in throttle response. The Idle went from 500-600RPM's to hanging around 900...where I like it. My A/F gauge no longer shows rich at idle...it just dances a bit like a narrowband always does. This only takes about 30 minutes to do, and helps the idle and throttle response tremendously. If you periodically do this, then you shouldn't have a huge fluctuation in idle when at stoplights.
