Just fitted the Beau desert 2.75 exhaust and have found that it is now not burning like it did with the original exhaust.

It is a bit fumy and smelly.
It also is giving small puffs of black smoke and sooty at the tail pipe.

Will a remap or dyno tune fix this and is it normal for this to happen?

I was wondering also is it to do with the smaller muffler and one less muffler from original.