One problem related to carburetor has been reported for the 1999 Ford Explorer. The most recently reported issues are listed below.
Throttle body/linkage, etc, fails and causes pedal to stick. While driving, truck will surge forward or stall with no warning. Pedal may also not disengage, reducing speed when released. Dealer found sticking iac valve. Check engine light on. Dealer found leaking intake seals and replaced.