collective wisdom - misfires

[Quiker]

I'm getting 'random misfires' - focused mostly on cylinder 4,5,6 -

I've look at all the obvious stuff, swapped plugs (again), had the intake off, ...etc

anyone with a similar experience?

I have a ton of bolt-on stuff - so I ran through hoses, tunes, ... but it feels like some sort of airleak in the intake... when I look at that side of the intake - the PVC nozzle is their... (I run the UPR catch can)

 

[FordTechOne]

If there is an air leak after the throttle body, it could induce misfires on the bank closest to the leak. I would recommend removing your UPR catch can system and return it to stock and re-evaluate to eliminate it as a possible cause.