Got a 99 3.0 4x4, one year ago. Its been good to me until recently. Had ABS fail, shortly after I got intermittent roughness and power loss, constant CEL and flashing CEL under load. Sea foam in gas tank, changed plugs, they all looked ok but old. Ran like a champ, then next time I drove it was rough again.Took it to a reputable shop, says code PO306, and back checked the ECM. No pulse to cyl. #6. Bottom line, they say I need a new ECM, recommend a factory rebuilt for $500 or so. Also said probably bad injector may have thrashed the ECM. Any link to ABS/ speed sensor? Any insight appreciated. Thanks for sharing.

 

Change the plug wires (one at a time) also.They can also cause a misfire.
What brand/type plugs did you use?

 

New Champion plugs, the shop did check the wires, but didn't replace. They swapped wires and tried another plug in #6 cyl. They removed the engine control module and back probed to find no pulse to injector #6, checked for pulse to two other injectors and were OK.

Of course it ran fine on the ride home, made an extra ten mile loop, no CEL, no ABS light but the ABS is definitely out. I think it may take a few more miles to register.

 

Dump the Champion plugs,these engines don't like them.
Use Motorcraft or Autolite.
The coil pack is probably getting weak.

 

second opinion said try the injector first so I bit. will keep you posted.

What's wrong with the Champion sparkplugs? Will they hurt my engine?

 

Fixed by changing injector, thanks for the suggestions.