Base Idle Set Screw (BISS)
The Base Idle Set Screw (BISS) is located on top of the throttle body, covered by a soft seal. But it's not just any screw. The BISS controls a throttle body air bypass that allows the adjustment of the idle. If your car is not idling right, it may be because the BISS has fallen out completely. The average Mitsubishi dealer seems to have no idea what this part is; we've heard of parts counter people claiming you have to buy a whole new throttle body to get the BISS.
We've got just the special screw, plus the important O-ring that holds it in place. Yours for hundreds less than a whole new throttle body!
|Rubber BISS CapThis cap covers the BISS screw, and can keep it from rattling out. Often the loss of this cap results in eventual loss of the BISS screw.