something leaking onto enhaust right side of engine. Smoking badly!

Always read the fine print people, it matters!

I take it you saw the "sizzling" on the flex pipe itself?

I almost thought I had it. If that drain hole (showing a residue ring) on the cab frame had been directly over the flex pipe, it would have been possible for rain/water to enter that channel maybe from another spot and accumulate in the channel, but in motion (accel or braking) might dump some of the accumulated water thru the drain hole and onto the hot pipe.
But doesn't look like that's the case, as the hole appears to be farther outward than the exhaust.

In any case, the white smoke would likely indicate water or coolant, not oil or diesel.

 

Based on the picture you are showing I would say it is actually an exhaust leak. When your truck begins its regeneration it begins dumping diesel in to the exhaust. That flex pipe is notorious for cracking. You would need a mirror to see it if it is on the back side of the pipe. a lot of techs over look this as it will only smoke during a regeneration. When it does smoke however it smokes a lot. Inspect the pipe with a mirror so you can look all around it. It will present a small black stain running parallel with the coils of the flex pipe. Hope this helps.

 

I replaced this flexible pipe 5-6 times , and is not cheap about 400$, stupid design.Are you lossing coolant? Did you check the EGR cooler? The 5th injector could leak diesel or coolant also.