1998 Mercury Marquis V8 Two Wheel Drive Automatic 159000 miles
When I am driving along and need to speed up my car hesitates and stumbles when I accelarate. We cannot locate the problem. It throws an EGR code, but the entire air flow system has be thoroughly cleaned, has a new EGR Valve and solenoid.
If it still popping up the code P0401 check the wiring and the computer-if its no longer showing the same code
could be caused by one of the following below: Oxygen sensor.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Manifold absolute pressure sensor.
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.