more windstar discussion

[rpbenisek]

let me get something straight. ford windstars 99-2003 are constantly plagued with DTCS codes 171-174 and every tech or mechanic has some solution and all these are entwined with variance of suggested solutions. the PCM does get it;s calibration in part largely from the MAS (right?) if this is the contributing source ,again we know there are also others. Can one make a specific check to verify the MAS by just simply unplugging and of course if the vehicle sputters & runs rough could this be a faster catch than all the voltage reading in the world?.As I stated before I had this problem for over 12 years in various shape and forms I will though be embarking on changing the intake gaskets & isolator bolts and clean the ports. I am expressing my thanks to all you and your true & honest reports, (thanks)

[wiswind]

MAF 'can' be a cause for this problem.
HOWEVER, the isolator bolt fix solved a vaccum leak.
A vaccum "leak" is air that enters the intake that has NOT passed through the MAF.
The MAF does a perfect job of measuring the airflow......then air leaks in from some location that is past that........the PCM (computer) does NOT know about this air, so you get a lean code because the fuel that was sprayed in was based upon the air that the computer knew about......

My point in this is........while the MAF can cause the problem, it is not even close to being the most common cause.

The 1999 through 2003 windstar used a much different upper intake manifold design (on the 3.8L engine) that had several parts.
The older windstars used a 1 piece upper intake manifold that also had the hold down bolts mounted externaly.