Eratic idle, sometimes dies on 1997 Ford F-150

Truck runs good until slowing down with foot off gas. When near stopping the idle speed surges ranging from about 1000 down to 400 rpm is worse when turning sharp corner or parking space then has a tendancy to die or surge forward. When standing idles steady at 700 rpm.

Asked by for the 1997 Ford F-150
You have sludge in the air induction system, idle air bypass passages and probably need to have the curb idle reset. E-mail me at and I can give you more details.
I would like tom know were idle air bypass is at and how to check it, plz email me at thank you