1998 Ford Windstar ODB II code P-0402

Hi, Normal Repair For this Code Is To check The EGR System And Related Parts. Their Are Other Parts Of The System Besides The EGR valve. Also The Mechanic Needs To check For Proper Vacumn to the Egr Valve. A lot Of Times The Egr Valve Is good, And Another Part Or Not Enough Vacumn, Due to A clogged Port. Is Causing The Problem. You Also Need A Scanner That can read Data From the Computer. To look At Different Sensors To See If They Are working Properly.

Hope This Helps You,
Good Luck
Edward S.