I need some help trying to figure out if the Invidia N1 catback will fit to my existing Cobb catted downpipe. The guys at IIR and Extreme PSI didn't really know for sure if they would be 100% compatible. Does anyone have these two parts on their car, and if so, could you guide me through the install??? Additional questions: 1) Do you use a donut gasket or the gasket provided by Invidia? 2) Do you use stock spring bolts or the bolts provided by Invidia?
cobb catted downpipe
cobb AP stage 2