Part one of Diagnosing spark plug foul. I changed the plugs out and still have an intermittent miss while cruising at low RPM when I hit the gas. Si here I am trying to fix the problem and giving some helpful hints along the way.
Replace Spark Plugs 2003 Ford Expedition
How you can change spark plugs in a 5.4 Windsor in a Ford Expedition. It took me about eight hours over two days. My engine was misfiring badly. This fixed the problem. I am slow and methodical.
Ford 5.4 Spark Plugs After 140,000 Miles
Ford Expedition 5.4 spark plug Gap after about 140,000 miles. I was getting hesitation off the line, then problem progressed to hiccuping under load, then finally it through a code and my truck went in to some kind of protection mode( 25 mph max) on the interstate. Got towed and and went to work.
No code misfire
So you have a car with a clear misfire but there are no codes. Don't worry, you can still use your scanner & labscope to quickly and accurately identify the problem and fix it with confidence without throwing parts at it.
Cylinder Misfires & Ignition Coil Testing
MotorWeek's Pat Goss shows what to check first when a cylinder misfire code shows up on an OBD scan tool. This includes how to test modern coil on plug ignition coils with a spark tester (available under "Extras" at RockAuto.com).
1997-2002 Ford Expedition & Navigator With A Strutmasters Air Suspension Conversion (Install Video)
Strutmasters (http://www.strutmasters.com/Ford-Expedition-Suspension-Parts-s/76.htm): (http://www.strutmasters.com/Lincoln-Navigator-Suspension-Parts-s/39.htm) This Ford Expedition Had A Sagging Air Suspension. The Owner Converted It To A Non Air Suspension Using Strutmasters Air Suspension Conversion Kit. Strutmasters Kits Are Designed To Bolt On Without Modification And Provide A Great Ride. If You Are Having Issues With Your Ford Air Suspension, Get One Of These Strutmasters Kits.