I have a 2000 F 150 with a 4.6, it started missing so i changed the plugs out and it continued to mis. I took it to a mechanic and the only code was for the EGR valve and a misfire in #8. I changed the valve and the sensor and put a new coil on the #8 cylinder. The truck is still missing badly and will not throw a code.

 

How many miles on your truck?

What plugs did you use?

 

#8 is driver's side firewall.

 

It has 184000 on it

 

What kind of maintenance? Fuel filter would come to mind. Also, cleaning the throttle body, egr ports... probably clogged. New set of cop's are probably in line also.