I have a 2000 f150 4x4 with a 5.4 v8. I replaced the thermostat and now i have a bad miss. Service engine soon light is on and stays on, I tried to read the trouble codes with a Code Reader but the Code REader wouldn't even recognize that it was hooked up to the truck. I checked the Code Reader on a different vehicle and had no problems with it so I know that it's working properly. Without being able to pull any trouble codes I don't know where to be able to start. Has anyone had any similar problems?

 

Check the fuses, you have a blown lighter fuse.

 

thanks for the help lxman1 after fixing the fuse and changing the plugs and one of the coils my truck now runs great.

 

Having the same problem. Had these symptoms before and found a cracked coil boot. Not the case now, all boots are fine. How did you determine which coil was bad? Appreciate any help.

 

I think he's saying he changed the fuse, then could read the code that indicated which COP was bad.

 

Yep, when I had a bad coil the scan tool tells ya which one is mis firing.