misfire below 1500 rpm

[arthurjarrels]

I had a heater tube leak on my 99, with the 5.4. Tore the intake off, fixed the tube. fired her back up, had a cylinder 4 misfire, changed the coil. now there is s steady miss below 1500 rpm. she seems snappy. Could it be a bad plug?

 

[tonydiv]

What exactly do you mean 'tore the intake off'?

Did you take off the entire intake manifold off, or just the throttle body?

 

[arthurjarrels]

had to remove the intake manifold, fuel rails, all 8 coils, vacuum lines, alt. to get to the heater tube.

 

[arthurjarrels]

Went ahead and replaced the #4 spark plug. Seems to have fixed the problem.