Fuel Injector
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect fuel injector harness connectors. Using a DVOM, measure resistance between injector terminals. See Fig 1. If resistance of any injector is not as specified, replace injector. If injector resistance is within specification, injector is okay. For additional fuel injector testing and specifications, see TEST HD: MISFIRE DETECTION MONITOR under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.