Exhaust questions?

[Potta_91]

Hi all exhaust questions here if you could help me so iv been looking through the forum and iv come to a decision that I'm going to gut the cat out and have a straight pipe to the backbox which I'm putting a centre box on. Am I best taking the baffles out of the centre box? And am I best to unplug the egr valve as I'm gutting the cat out? Also is there a lamba sensor I need to do something with? Thanks in advance mark