P0302 Cylinder 2 Misfire Detected P0303 Cylinder 3 Misfire Detected I suggest you replace all spark plugs, and plug wires. When you purchase the plugs and wires, tell the parts store the codes and ask them to reset the light after you install the parts. See where you stand after the repair. I would also run a compression test on all cylinders to see if you possibly have a burnt valve or blown head gasket, which is unlikely, unless you have symptoms of overheating or missing, especially after you replace the above items.
The V8 engine has ( 8 engine cylinders )
The V6 engine has ( 6 engine cylinders ) * EFI and SOHC * The 5.0 liter V8 has ( 8 engine cylinders )
In a 2002 Ford Explorer : The 4.0 liter Single Over Head Cam , V6 engine has ( 6 engine cylinders ) The 4.6 liter Single Over Head cam , V8 engine has ( 8 engine cylinders )
Wheel cylinders are in the rear drum brake between the shoes. The Engine's cylinders are in the engine block, under the cylinder head.
If it has the 4.0 liter V6 engine there are ( 6 engine cylinders ) If it has the 5.0 liter V8 engine there are ( 8 engine cylinders )
For a 1998 Ford Explorer : The 4.0 liter V6 engine ( either the EFI or the SOHC version ) ( have 6 engine cylinders )
The only factory engine in a 2004 Ford Explorer Sport Trac is the 4.0 liter Single Over Head Cam , V6 engine which has ( 6 engine cylinders )
Cylinder #4 is misfiring in an engine with 4 or more cylinders. Engines have a firing order that is used to number the cylinders and it depends upon the engine which one is #4.
The fuel in the cylinders exploding
If you have a "check engine" light on, start with having the codes read. A misfire code can tell you which cylinder or cylinders are having problems. A misfire could be the cause of your engine vibration.
6 or 8 depending upon the engine.