I replace most everything it said to do but it stills ildes smoths then it surges 700 900 rpms
MY tauras check engine light is on i ran a obd2 test it came up PO174 on 2005 Ford Taurus
system is lean bank 2 ck for vac leak with smoke test and or poss injector issue
lean code on taurus... I lean towards the vacuum leak as well.get a garnen hose and dribble some water around the intake and at the top of the intake there is a large round o-ring that goes bad as well.I'm sure you will hear a "slurp" somewhere while doing this.Let us know what you find!