dizflyaznboi

i know that the s4 needs the backpressure from the cats for the 5th and 6th ports, but what if i get a straight pipe with a resonator test pipe. Could i use that to replace the cats and would it create enough backpressure for the ports?

Sideways7

iTrader: (7)

You need the tube coming off the cat (or something similar) to get the pressure to the aux ports to open them. A test pipe will not have this, and even if it did you prob wouldnt have enough backpressure to operate them. There is a fairly simple writeup on how to electronically operate them, I think in the archives.

DeclareYrWar

^correct or you could get the precilencer from racing beat for the s4 which has that tube on it. they flow really good, i have one on my s5 and it made a huge difference in power (i also got their cat delete for the 2 precats)

dizflyaznboi

what if i just gutt out the cats, would i still get the power and the backpressure needed?