Re: 2001 windstar w/P0171 & P0174
Here is the fix. The air intake plenum has loosened up. Take the upper air intake plenum off and tighten the lower one. You may even want to replace the gaskets while you are at it ($120.00 from autozone). Too much air gets into the intake and gives false readings at your sensors. The fix is easy, takes about 45 minutes.