P0172/174 and now p0301/303 TSB repair done yet no luck. HELP?

[Lynn90780]

2001 Ford windstar. 3.8

It has the popular 172/174 codes It Idles real rough, Hesitates, and lacks power under acceleration.
Following th TSB I installed:
New upper intake gaskets:
Isolator bolts:
TB Gasket:
Cleaned the EGR ports as they where very dirty.

Still showing those codes plus p0301/303 "misfire on 1 and 3"

So I then Cleaned the MAF, New fuel filter and plugs.

Still no luck.

EGR valve seems to work Using Human suction on the EGR vacuum port.. It does open and close freely.

I am at a loss.. please any ideas??

Erik Baxter