This 2003 Ford Windstar came in with the service engine soon light on. Checking code revealed codes P0171 and P0174, banks 1 and 2 lean. I checked for vacuum leaks and none were found so I moved on to the Mass Air Flow sensor. It is common for them to get dirty and cause these fault codes. The MAF sensor is located inside the air filter housing so it had to be removed. I loosened both hose clamps and pulled the rubber boot from the throttle body and then from the air filter housing. Then I unlocked the spring clamp that holds the two halves together.
The crankcase ventilation tube also had to be removed from the rubber hose and more importantly it has to be put back in place during assembly. You can see it just to the left of the master cylinder.
After unhooking the wiring harness connector I took the housing to the bench for dis assembly. There are several locks that have to be released. I used a common screwdriver blade to pry them inward while pushing the sensor out from the other end.
There is also another wiring subharness that has to be removed. It is kind of a pain but I take my time so as to not cause any damage. Once the two halves were separated I removed the sensor from the housing using and tamper resistant torx bit socket.
This is were the actual sensor elements are located and in most cases you will find a build up or film on the element. I use a pick as shown or a small screw driver and very lightly rub the film off. Sometimes if it is heavy it will lift off in one try but most of the time it takes a little while of very light rubbing to remove the film. Some people use cleaners but I prefer to manually rub it off so as not to cause and damage to the sensitive parts. Many cleaners will damage the plastics.
Just several different pictures of the same sensor. There are two elements inside and the most problematic one is the one further inside that you cannot see.
This is just one of the possible causes. There are many and one of my readers left a link to a repair site that has more answers on this problem.
Ford has a TSB out on this for 1999 to 2003 Windstar. if you want to do it yourself, you need to go to your local parts store or dealership and ask for a “Valve cover repair kit”. This site link gives step by step instructions for the fix.
If the large rubber tube is not properly clamped or if the small hose that goes into the side of it is not properly installed, then yes.
I changed the Air Filter 3 days ago. I drive this car as a taxi.
The “check engine” showed up and when I checked the codes, I got P0171 and P0174.
Could be that I changed the air filter incorrectly?
It is a 2002 WindStar.
Ford has a TSB out on this for 1999 to 2003 Windstar. if you want to do it yourself you need to go to your local parts store and ask for a “Valve cover repair kit”. This site gives step by step instructions for the fix http://leckemby.net/windstar/windstar01.html I have the PDF copy of the TSB if anyone would like it i can email it
Sadly, it is a common problem with all cars and not just Ford products. The build up on the MAF sensor is only one of the possible causes. Other causes are restricted fuel flow, vacuum leaks, exhaust leaks before the o2 sensors, too much ethanol in the fuel and software issues. Each manufacturers body platform has their own unique issues. One thing that I have learned over the years is that there is nothing made by man that is not flawed in some way.
Well, this didn’t fix mine. After I reset it, the check engine light came back on about 5 hours later. So, I did the reset again. This time is stayed off for almost a week. So, I guess I’m at the mercey of the Ford Dealer. Thanks for all your time and this great post.
I’m the third person at work that has a Ford with this generic code. I really think Ford should have been forced to do a recall fix for this problem, since it’s clear it’s a problem with their cars. I’m striking Ford off of my list of cars I’ll ever buy again.
Thanks,
Craig