Question about 1999 Ford Windstar
PO171 and PO174 "System adaptive fuel too lean (Bank 1)" and "System adaptive fuel too lean (Bank II)" The first time this happend I was told by the Ford dealership that I had an upper intake vaccum leak and that I had to replace the upper intake gasket and the 6 port seals. I did this and my problems went away for about 8 months. Now I'm getting the same codes with the new gaskets. The shop said it could be a Mass Airflow Sensor, but those are expensive if it's not the problem. I've replaced the PCV valve and the fuel filter in the past year. I did new plugs 2 yrs ago and I've installed a K&N air filter. Could my problem just be a leaky hose or something? What would cause both banks to lean out? It has started Idling a little funny at times and it surged the other day. Do I need to dig back into the Intake or is it an MAF sensor? Please help with any tips for diagnosing this problem that you can. Thanks.
If they did not replace the front valve cover with a new updated one when they did the intake the code will come back.there is a tech service bulletin about this . your mass air flow sensor can be cleaned but would recommend a shop do this.
Posted on Feb 01, 2009
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Tips for a great answer:
Dec 02, 2012 | Ford F-150 Cars & Trucks
Jun 26, 2017 | 1999 Ford Explorer
Nov 11, 2010 | 1997 Ford Expedition
Jul 06, 2010 | 1999 Ford Taurus
Nov 05, 2009 | Ford F-150 Cars & Trucks
Sep 16, 2009 | 1997 Ford F150 Regular Cab
Jul 06, 2009 | 2003 Cadillac Deville
Jan 15, 2009 | 1995 Ford Windstar
342 people viewed this question
Usually answered in minutes!