Auto Zone will check your engine codes for FREE... It be a bad coil pack, bad plugs or wires..
The 2003 Ford Expedition has a V8 engine.
There are several things that can cause your 2003 or Expedition to misfire. The most common cause is a plugged catalytic converter.
The 2003 Ford Expedition has a 4.6 L base engine size.
The 2003 Ford Expedition's engine produces 232 hp @ 4750 rpm.
The 2003 Ford Expedition's engine produces 291 ft-lbs. @ 3450 rpm.
i have a 1998 ford expedition and i had simaliar to the same problem. does it feel like your loosing power? on my truck it was a misfire on my engine coil i would get that check out
Engine misfire. Possibly a bad coil or spark plug.
You can find an engine diagram for a 2003 Ford Expedition in the vehicle's owner's manual. You can also find it at certain auto stores.
On a Ford Expedition : Bank 1 is the passenger side of the engine ( 4.6 and 5.4 )
Check Ignition Coils Check Ignition Coils
In a 2003 Ford Expedition : The ( 2 valve per engine cylinder version ) if that is what you are asking
get the engine serviced.