Replaced 2 rear cats with straight pipes today.Definitely comes up more power.I can feel is.The rear cats are very restrictive,at least 400-cell..

Now my 3.6 v6 have done K&N filter and 2nd cats removal.Do you think it worth to do the ECU tuning for a 3.6 DFI v6?As in the sport model I can feel the car even more powerful than my previous standard 05 4.5 v8 now.I heard ECU tuning for a v6 cayenne is waste of money it wont add more than 5hp..Is it true?

 

What about the exhaust sound? Big difference?
I just got my Cat Bypass and BMC filter too.
Will install it on Sunday... CANT WAIT!

 

More than 5 hp, somewhere between 10 and 12 hp depending on the other mods(exhaust, intake).

 

What bypass pipes did you guys use?

 

I ordered a set of Fabspeed from Alex.

 

I dont think ECU tuning is worth it i didnt do it on my V6. How does it sound with the straight cats is it a good sound?

 

I'm having my ECU remapped after Christmas. I'll let you know my thoughts.
The tech claims a 35HP-40 HP gain and a much smoother throttle response..If it's true, that's quite significant.

 

do you have a v6?

 

No, ctt.

 

The muffler still stock so no moch improve for sound.A little deeper anyway.Car feels more responsble in non-sport model.

 

in a v6 i herd ecu tunning is kind of a waist it would only ad about 5hp

well i have custom mufflers and i think they sound excellent but i want to make the cat bypass pipes straight(for more power) thats what you did right? Do you think it will ruin the excellent sound of the mufflers? and also did it make anydiffrence in gass mileage and what about power in sport mod is it the same in power as regular or even more?
thanks

 

how much HP gains for replacing secondary cat pipes??