The 2000 year 3.4L 4Runner has no add on EGR system... plumbing, valves, etc.. It must use cam timing overlap or some other trick to do away with the add on hardware...

Based on your comments about the OBD-II seeing the drop in TPS values, that sounds like a strong suspect..

Sounds like the next thing is checking the resistance readings on the TPS per the FSM.. I'd look for noisy readings as you slowly turn the input shaft... sounds like the potentiometer is making bad contact at the point where it hesitates...

If you see a noisy spot, confirming that's the problem, you got nothing to loose by spraying the pot contact area with contact cleaner/lubricant.. There's a flavor of this stuff made specificly for noisey pots..

I'm assuming the pot contact area is exposed by popping the plastic cover off the TPS as can be done with older versions of Toyota TPS switches.. could be wrong on this....

I just bought one for my wife's Camry and it was only about $70.00.. Hopefully the one on the 4Runner is not too expensive..