If you are gonna turn up the boost at the very least you need to install a catless uppipe. The factory catted uppipe has been known to disintergrate and destroy turbos. Also, as most everyone else has stated it is not advisivable to run that much boost on a factory fuel system. Something in the 15 PSI range is much safer and you will be quite happy with the results.

 

should you replace the uppipe if you're going to go 15-16 psi?

 

As I understand it, the increase in EGTs is what can cause the preturbo cat to fail. When you increase the boost via MBC or EBC the engine is running a bit leaner thus, higher EGTs. Also, when you increase the boost via these methods, it also holds much higher boost until redline. Unlike the stock boost control that tapers boost off quite a bit after peaking. So, even increasing boost to 15-16 PSI which, on paper does not sound like that much, but it is holding that higher boost longer. I am not saying you cannot run the factory uppipe but for the $150-200 in cost it is good insurance (not to mention an increase in power).



Please feel free to correct me if I am wrong on this.