hi guys i plan on buying a 2 1/2" test pipe to put in place of this pre silencer and cat i got. it goes from headers to pre silencer then cat. im just gonna cut the flanges off and weld them onto the test pipe. so since i have an s5 and dont need back pressure to activate the 5/6 ports can i just disconnect the air pipe in the engine bay that connects to a rubber hose and throw it aside?

 

Yup.