05SPLIFIN

Hi, i dont have the budget to go an buy a $1,000 exhaust. if i were to cut out the catys and just weld 2 straight pipes going to the back, how much mpg will i loose, whats the power difference, and sound ?

thank you

shawnoc2003

No idea, but you'll probably get a CEL unless you move the 2nd set of o2 sensors downstream.

Full mileage should go up especially if the cats are high mileage. Sound will get a little louder but not too much. You probably want to do away with the pre-cats first.

skip01b5

You could just gut your pre-cats first for piggies, or if you just wanted a catback, SSAC is doing a big sale right now on them. Its a copy of the AWE Twin 1.Havent heard anything bad about them either, and shouldnt be too loud with stock downpipes, itd be louder with piggies though

http://www.audizine.com/forum/showth...ATABLE-Pricing!

05SPLIFIN

how far down should i move the o2 sensors ?

05SPLIFIN

Good prices too !

05SPLIFIN

oh, but what about a straight pipe after the stock catys?

imola_s4

Im replacing the clutch and flywheel on my s4 so i have the dps out and im sooo tempted to make piggies using the defouler mod for 02 sensors,would i need to get a tune? ive heard i do in order to make the car run lean is this true? or will it be fine without it i have a borla catback btw.thanks

05SPLIFIN

defouler mod ?

imola_s4

instead of moving o2 sensors behind the cats you just put sparkplug defoulers/nonfoulers so that they are a bit farther from the cats this tricks them into reading normal levels

05SPLIFIN

thanks