Two things I can think of:
(1) The throttle plate set screw has been adjusted from the factory setting.
(2) There is a vacuum/air leak somewhere or a vacuum line not connected.
If you disconnected the battery during the install, it will take a few drives for the computer to relearn its parameters. If this is the case, start the car and let it try to idle without touching the gas pedal. If it stalls, restart it and let it try until it relearns what it needs to idle smoothly.
The different sized barbs are to allow the intake to be used in a 96-04 Mustang 4.6L engine which had 2 or 3 different vacuum line/manifold connection hose sizes over the years. Use the one that fits your application.
(1) The throttle plate set screw has been adjusted from the factory setting.
(2) There is a vacuum/air leak somewhere or a vacuum line not connected.
If you disconnected the battery during the install, it will take a few drives for the computer to relearn its parameters. If this is the case, start the car and let it try to idle without touching the gas pedal. If it stalls, restart it and let it try until it relearns what it needs to idle smoothly.
The different sized barbs are to allow the intake to be used in a 96-04 Mustang 4.6L engine which had 2 or 3 different vacuum line/manifold connection hose sizes over the years. Use the one that fits your application.
