mackattack3

i got a 2013 and ive put the k&n short ram intake on it with the magnaflow cat back exhaust and the car sounded and ran good. monday my invidia test pipes came in and i installed them. the things sound like **** from 2-3g reving up or down. making a hissing sound and throwin 02 codes. does anyone have any sugestions to stop the hissing just to make the car sound good instead of a old junker.. worse comes to worse im just gonna throw the stock cats back on