My CEL came on the other day then turned off on its own then came back on. The next day durring normal driving the turbo completely went dead. No pull at all, hiss from the intake or expulsion from the BOV can be heard to confirm this terrible fate. After some trial and error the dealer says the pre cat melted somehow and thats why the turbo isnt spooling. They want over $500 to replace the pre cat. Should I just replace the pre cat with an up pipe? How difficult is it to install?