I have a 1999 ford windstar with a sputtering/stalling issue. The car runs perfectly when I have pressure applied to the gas pedal but as soon as the car slows or when I am idling the car gets jerky and feels like it wants to stall. If I keep 1 foot lightly on the gas and hold the break at redlights the car is fine. I cranked it the other day and the engine made a loud POP with white smoke coming out. When I opened the hood to investigate the PCV hose and come off of the intake. I believe that is the only source of the loud pop and smoke, but I am not 100%. All of the sputtering and jerks started after this incident. The PCV valve is pulling strong but has a thick buildup around the grommet and inside the hose and the crank case. Any ideas of what the issue could be?