which oxygen sensors upstream or downstream
upstream= before cat, downstream= after cat.
O2 might not be the problem, only detecting the problem. Do you have a misfire and vacuum leak? Scan for codes.
Bad O2 sensor will not stop car from starting or idling. As Tom said, scan for codes.
Looking for a Used Windstar in your area?
CarGurus has 691 nationwide Windstar listings and the tools to find you a great deal.
Search Ford Windstar Questions
Ford Windstar Experts