Modding the AFM involves cutting the silicone seal around the black cover to gain access. Once inside, there's a "curly brace" looking metal clip in the upper left corner being held down by a Phillip's screw. Mark with nail polish or similar, the original position of the end nearest "12 o'clock" on the large wheel (arrow #1). Then, with needle-nose pliers or a large flat-blade screwdirver at arrow #2, pull/pry the end of the brace out of the wheel's teeth. Turn the gear wheel clockwise to lean the running mixture, and counter-clockwise for richer. The idle mixture is affected by this adjustment, so you may have to adjust the bypass after the main adjustment is satisfactory. Do not adjust any more than 3 teeth in either direction with stock injectors. Supposedly, a stock system shouldn't need any adjustment, and won't benefit much from changes. It's a trade-off; leaner can sometimes help off-the-line, richer adds to the top-end. The AFM should really ONLY be adjusted when you have reached the limits of the stock injectors and have had to replace them with larger units.

You can adjust the idle mixture by carefully drilling out the aluminum plug in the lower right "corner" of the AFM near the outlet to the throttle-body. Tightening the screw beneath the plug makes the idle richer, loosening it leans the mix.

Another item to consider adjusting is the throttle-position sensor itself. It's the black square box on the driver's side of the throttle-body. There's 2 screws that hold it in place. Loosening them allows you to rotate the sensor. Clockwise advances the changes relative to throttle position. Too far and you'll "disable" the idle position. If you retard it too much, you'll go into lean misfire around 3000 rpm. It should go from idle setting to mid throttle around 2500 rpm, I think. The plastic cover comes off so you can see the switch actions inside, which may help in adjusting it.

Stock specifications & adjustment procedure are here

"My" procedure for adjusting the TPS is to *slowly* bring the revs up and see whether you hit a fuel-cut around 2200-2500 (maybe sooner) rpm. If you do, you need to advance the TPS (clockwise, looking @ the TPS) slightly & try again until you don't get the fuel-cut. Hitting the fuel cut means the TPS isn't coming off the IDL switch soon enough.

Q: I heard that TRD [Toyota Racing Development] has a street legal cam made for the 22RE. I was wondering if any one has heard any reviews on this cam. I'm wondering if I should go and buy this cam for my 4runner. Or should I get one that's not legal and just switch between stock everytime I go for a smog check...

I don't know about TRD cams, but I have run a few different ones. The stock flapper door EFI should handle a pretty wild cam, but it may not pass emission testing. With my programmable EFI [Electromotive TEC-II] I just got a CompCams 268S to pass with flying colors. All I needed was a new cat and late ignition timing. It was very clean so I think it would have passed with my good driving settings. There is no doubt that the stock cams kills these motors. Even a mild torquer cam is a big improvement. For a stock computer, I would go with a duration less then 260. I think the street perf CompCam was around a 255. They had an all out race cam that was 280 butI doubt it would idle at all. Crane cams makes split pattwern cams with larger exhaust side to compensate for the smaller exhaust valves. I used equal pattern for the turbo.