Ford Repair: EGR VALVE, ford windstar gl, air fuel mixture

Question
How difficult is it to replace an EGR valve in a 1995 FORD WINDSTAR GL 3.8.?  I can hear and feel knocking coming from it. Thanks!

Answer
EGR Valves almost NEVER need replacing.  A common repair is cleaning the EGR ports in the intake manifold.  The ports get clogged with carbon and cause a "lean" air-fuel mixture, this causes detonation (spark-knock) on acceleration.  EGR Valves are not hard to change, but are somewhat expensive.  I would recommend having the vehicle diagnosed by a Dealer before spending a couple hundred dollars on replacement parts.

I hope this helps,
Dave