how to know which oxygen sensor is bad on 2001 Grand Marquis
Test them. http://www.autozone.com/repairinfo/common/repairInfoMain.jsp? targetPage=productsHowToInspect&leftNavPage=productsHowTo&p ageId=%090996b43f80a01215&subtitle=test
Personally I think it is easier to replace them.
Yes,agree, and have bought 2 Bosch 15717 oxygen sensors. Predictive maintenance practice supports your recommendation. Thank you.
Looking for a Used Grand Marquis in your area?
CarGurus has 2,250 nationwide Grand Marquis listings starting at $1,500.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts