Im planning on buying a full exhaust from the turbos back.

I've been looking around and have found a stainless downpipe, highflo cat, and not definate on a cat-back yet.

I was wondering if the highflow cat is worth it or should i just keep the stock cat?

also with a down pipe do i need a boost controller?

and if anyone has done this upgrade what was your hp increase w/ or w/o a high flow cat? Let me know

Thanks again,
Justin

 

If you're asking about a boost controller to lower your boost levels, that's not what a boost controller does. A boost controller will only raise your boost above the level that the wastegate limits it to. If you want to keep your boost from creeping with a full exhaust system, you need to port your wastegate. Do you have any other modifications? Most people recommend only changing the downpipe and catback before getting an upgraded ECU.

 

hiflow will give you better performance compared to stock main cat.
and with higher flowing exhaust you will get slight increase in boost. you can get a manual/electronic boost controller to set the boost back to 10psi if you still have stock ecu.