2006 Ford Explorer

Engine Performance problem
2006 Ford Explorer 6 cyl Four Wheel Drive Automatic 46000 miles

Check engine light came on, and had the code read. It was a number 5 misfire. It runs bad a an idile and when I put a load on it, it runs wrose and has a surdge. When driving, it makes a back pressure sound. I have replaced the spark plugs, wire, coil, fuel filter, and fuel injector. When pulling the spark plug wires, when running, a change in engine on all wires except 5 & 6. I am now lost and don't know what to do next. Can you help?
December 16, 2008.

Have you done a compression test
I would
when you pull the wire of the spark do u have spark on it
checked the injector pulse

Dec 16, 2008.
I have done a compression test and all range between 185-195. When I did pull the wires, all wire do have a spark. How do you check the injector pulse?

Dec 18, 2008.
Locate the injector and pull it electric connector and check
use a small light bulb (194)
or a noid light
place in the plug and it should flash on off when engine running

Dec 18, 2008.