News bits fitted courtesy if Biff

[Rudeyboy18]

I recently bought biffs dual exhaust and Bosch maf. And I'm very pleased with results. The exhaust has a none intrusive tone overall but sings a nice note when you boot it. The most impressive thing for me is that the "boost leak/screaming " noise over 1bar i had before fitting the maf has gone. I kept getting a lean code coming up and lambda light often on prior to fitting the new maf. The old maf was a cheap imitation i believe and comparing the 2 side by side you can see a huge build quality difference.

Can someone explain how and why this is the result?? Pics to follow after I clean her up abit