Makes sure you post the year, engine, and transmission info on your car when asking for help. That way we know what to reference.
The 95 still used 3-digit EEC codes. 96-on used the 4-digit "P" codes.
Run this quick test:
Disconnect the vacuum line to the EGR valve. Attach a short piece of rubber hose to the valve connector on the EGR valve. With the engine running at an idle, suck on the hose like you're trying to drink a milk shake. Did the engine drop RPMs or even stall?
If yes, the EGR valve is good and the intake passages are clear and the problem is elsewhere.
If no, either the valve is bad or the passages are blocked.
A mechanic should know to do this.
A description of the Ford EGR system is available here:
http://www.smpcorp.com/download/view/tt2q00.pdfSteve
