3.4L TRD Supercharger part:
One-way Idle Air Control (IAC) Check Valve: PTR26-35042 (~$5.99)

Commonly overlooked part when installing TRD supercharger on 3.4L Tacos/4Runners. Part number supersedes the old TRD number.

'99 Tacoma Xtra cab V6 TRD
TRD Supercharged, URD 7th injector and 2.2" pulley, 32X11.5 BFG All-Terrains, OME 881 3-inch lift/Toytec AAL, 5100 Series Bilsteins all around, and ProComp 130 lights.
No I'm not some creepy naked guy...