LivinSideways

i was wondering what will happen if i take my cat on a s4? do i need the back pressure? thx

synesthete

If your N/A you need backpressure to open your 5&6 ports. This is sensed thru a split air pipe attached to the cat. If you remove the cat then you have to do something else.

If your turbo you dont need backpressure.

LivinSideways

is there any thing i can put in to keep the 5th and 6th workin but still keep the cat

misterstyx69

iTrader: (142)

just hollow the cat out..you still have the tube on the cat for back pressure..cheap and does the trick..Or do an air pump "mod"(loosely put)..(search... aux ports air pump activation)..anything you may be doing or attempting to do is usually in the second gen archives..(not gonna rag ya)..may I suggest a little reading..It will really be informative..(friggin amazing stuff in there Bro..)..ya!..post 800..(woot!)

Icemark

Not quite accurate...

You need exhaust pressure, not back pressure.

However removing the cat removes the line for the aux ports to get exhaust pressure to open the aux ports.

Back pressure is bad for all cars, regardless of if they are turbo or not.

wambugu

One possibility http://www.aaroncake.net/RX-7/6portfix.htm
or a writeup for wiring them open https://www.rx7club.com/showthread.p...ght=port+wired
Just a couple ideas. Get creative think something up that would open those ports. There is a lot of searching here. But I guess if you don't know what to search for. There are several solutions to this. Ok a couple people posted since I started typing. So removing the cat just got a lot more complicated.

LivinSideways

with no back presure on a pison engin ull burn out the exh valve ill know some stuff just new to the rotary club

Icemark

only on a poorly designed engine