1998 Windstar 3.0 with PO171 & PO174

[jgbmo]

I'm not sure if it was the new vacuum management control valve (Motorcraft part# CX-1669, purchased from O'Reilly's for about $40) or the new PCV, but the car is running like a champ now, and the CEL is staying good and dark. The car starts great when cold, idles smoothly, and exhibits no nasty behaviors.

If I had to bet, I'd say it was the PCV that had been causing the problem.

BTW, I checked the new vacuum management valve, and it doesn't hold a vacuum either (just like Dngrsone said), so you were right on the money.

Thanks for all your help!