Been thinking about custom tunes for a long time but I was told 4.6 motor doesn't run lean like the 5.4. Is this true, I hope one of you guys knows. But I still think custom tunes are in my future.

 

custom tunes are always better than canned tunes...



it's not the 5.4 engine that runs leans it's any 3 valve modular ford whether 4.6 or 5.4, since your truck has a 2 valve motor you can run a CAI without issue but you'll see more gains from custom tunes

 

ANY engine that has a modified MAS/MAF will need a tune.

The reason why the tune is required is because it is a tonsil/slot-style and the housing changes, and that changes how air is flowed across it.

 

That's exactly how it was explained to me by the tuner, too.