is my MBN right?

Check out this thread- Finally! My MBN flashed to 6NZ

 

I think that's supposed to be kinda normal for MBNs, but I have no experience with them myself. If you're going to find someone to change the injector codes, you should really consider just getting Mr. Haney to go ahead and flash it for you. It's very reasonable for the results.

 

That sounds pretty good for an MBN do you hand calc it? You're lucky your egt's are good. I could push 1200* and beyond easily (I let off the gas at 1200) many times during the day. I could wash my truck and the stack tips would be covered with soot in only 500 miles. Now it still does it but takes about 5000 miles to look as sooty as it did when stock. If you can't afford the turbo now at least try the 6NZ 2300rpm brakesaver flash and block the wastegate off on the stock turbo when you do. I would have been happy with that alone but my stock turbo was shot it had to be replaced. Haney told me tweaking trim codes would give about 40 more hp but advised me in the interest of better mpg's to leave them stock so I did. Also wanted to add my oil stays cleaner longer. It would turn black pretty quick with MBN files. Again Haney said it would do that. Flash it 6NZ and put some free flow mufflers or run straights and your soot levels will go down.

 

5.5 isnt bad for what you have. At night when idling mine used to haze and pulling hills would do the same painting the trailer sides black. Since upgrading it doesnt put any soot on trailers at all no matter how long i may have one. No hazy idling and no smoke on hills. Your motor will be more efficient and run like a raped ape if you 6nz it.

 

Whats your boost under load? Have you checked your turbo and manifold, it my be running rich if the center manifold is burned out. ( common on MBN )I also suggest this due to you have a 525 hp with a fuel wire and the engine is not derating with excessive boost faults under load.