Hey I searched but couldn't find a deff. answer,
I plan on taking my cat off tomm.
well this is my first s5, ( 3s4's)
I was reading that the 5/6ports operate sole'ly on the air pump,
But then I got under my car and saw a split air pipe, just like what was used to activate the 5/6prts on my s4,
I read (couldn't find a deff. answer) that the split air pipe on s5's have nothing to do with the 5/6prts, It is just there to help the cat breath,
Is this true? I plan on throwin on a straight pipe but my 5/6prts still work and I would like to keep it that way,
thanx for the help guys!

matt-

 

no point in getting rid of your car on a NA either you wire your 5th and 6th open lose low end power or you leave it the way it is and stay the same, the ports open off the exhaust back pressure

 

All FC's have a split air pipe. It's purpose is to deliver air from the air pump (via the ACV) to the cat to make it work better. For S4 NA's it's also used as a source of pressure for the 6PI system. The S5's 6PI system only uses air pump pressure.

 

I appriciate the comments I know the results of losing the cat.
so
NZConvertible, If I removed the split air pipe, my 5/6prts would still work fine correct?

 

for S4's, not S5's
thats the whole reason for this post..........

 

Correct.