I am having the same sort of problem on mine... 1999 110,000 miles. I cannot seem to find a vacume leak and i am holding boost well. The idle when i initally start the truck up cold is very erratic as well until it starts to warm up some and then its fine.


1999 4-runner
TRD Supercharger, 5 speed, 2 inch pulley, Dual 2.5" exhaust, AEM Brute Force Intake, Supra Injectors