I have a 2001 dodge 5.9L in a motor home and it keeps giving me a 306 code, misfire in cylinder # 6. I tried changing the spark plug, wire, and fuel injector and gasket for throttle body. I cleaned the IAC valve and air cleaner to no avail. Any idea on what it may be? Thanks for any help you can give me.

 

Do a compression test on it and let us know what you get for PSI.

 

I had a similar issue and I had a burnt valve and a cracked head

 

what test did you do to determine that?

 

What alloro said

and this:

 

Too cold to do that now so it'll have to wait.

 

Replace distributer cap and rotor, buy the best you can get. Contacts must be brass not aluminum. You'll never get more than 3, maybe 3.5 years out of a cap/rotor set on these engines before they start to misfire.

If it is still misfiring with a known good cap/rotor it is either spark plug wires or spark plugs. Brand matters: I recommend either NGK (factory equipment) or Autolite, depending on your preference.

The 5.9L heads aren't likely to crack, though anything is possible.

 

Did all that and cleaned/swapped fuel injector with #7 cylinder. Got a nice steady 23 inches of vacuum, seams to idle smoother. Will take it on a run after the weather warms up. Thanks for the suggestions.

 

Glad you got it sorted out

 

Had it out a couple times, running good so far.