Sup everyone.

stock N/A S4

Im about to swap out my exhuast manifold for RB ones that i bought off someone here on the forum, also bought the cat back exhuast and it came with Mazda Cat.

just wanted to know if there was anything i need to watch out for while doing the swap. i got the gaskets from mazdatrix so i think im ready to go.
ive done this on hondas before but i just wanted to check in with rotary gurus 1st. dont wanna miss anything. i have the haynes manual just in case too.

 

You should be fine, as long as exhaust isnt uber rusted.

 

You will need to either wire the auxiliary ports open, or find a way to actuate them, as they are opened from the exhaust back pressure stock(on the s4's), and once you go to a free flowing exhaust there is not enough back pressure to open them.

 

^ eh? and how would i wire them to do that?

 

keep the cat and they will work fine.

 

.

 

yay! got the exhuast in..

it was a pain to get the old crappy exhuast out. the stock mani was basically welded to the cat so it wasnt fun to get out. also that damn heat shield was pain and the two upper bolts were hard to get to. i had remove some small air pump like thing with a pin on top that goes in when you push it, (dont know the technical term of that part) but there are two of them each hiding the upper bolts on the Stock exhuast mani. Once i got those off it was easier to get to them. I did need to go to autozone 2 times cuz i didnt have the right size socket extension to get to the bolts, nor did i have an o2 sensor socket to remove it. Mani came off then just had to man handle it out the bottom of the car ( i had a friend help me the whole time.)
after that removed what was left of the old gasket, put the mazdatrix one on and slipped that RB header right in. was soo smooth to fit like a baby's bottom. after that everything was cake.

i dont think this qualifies as an official write up but at least if some other noob asks "i got a thread for that"

one quick question tho,

the O2 sensor wire isnt long enough to from where the whole is on the headers to reach the connect on the engine. so i have O2 right now. car doesn't idle funny or anything and i still have my air pump, is there a rig to extend that wire to the connector? and am i gonna have any issues running with no O2?

 

im sorry, but if you cant figure out how to swap out something as simple as an exhaust, then ... idk man.


the stock o2 sensor is only used durring cruising. thats when the gas milage will suffer. just connect it with a length of wire.

 

lol, hey I got it swapped I'm just saying that to get to the bolts at the top was slightly harder than I thought. And thanks .

 

Sounds like you took out the 5th/6th port actuators. While they're out, be sure to clean them real well. Theres a writeup in the archives I think. You probably won't need to rig them up electrically, but that depends on what size piping you went with as well as how high flowing the cat is.