Diagnosis: P2195 01/04, P2197 02/04, Po171 03/04, Po174 04/04
Believe it or not but all 4 codes are referring to a lean condition, possible fuel supply or pressure, also check for unmetered air into the system. so check for vacuum leaks and intake manifold leaks.
yes as tennisshoes said check for vacuum leaks.
Wat is oem number p0201 and p0204
Looking for a Used Grand Marquis in your area?
CarGurus has 2,558 nationwide Grand Marquis listings starting at $1,300.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts