2002 Taurus 3.0L stalling:
 

Hi a friend of mine recently purchased a 2002 Ford Taurus SE 3.0L SOHC
(Vin 2) with 75,000 miles. Prior to some normal PM, replacing the
plugs and filters, servicing the transmission, the car sometimes
stumbles and faulters, stalling when coming to a complete stop.
Addressing this no-code driveability problem, I replaced the IAC
motor, serviced the throttle body, and installed a new wire set. Great
for a day then the same complaint. Wait, there's more.. a chirp
(sounds like a serpentine belt) however it hovers around the intake,
near the TBI unit.
Am I chasing a vacuum leak? Are these new dual plenum intakes
experiencing gasket failues?

Thanks a bunch for your reply,

Bush