Invidia R400 Cat Back Exhaust Fluid Pressure Sensors 100% of the airflow is

100% of the airflow is cold air being brought in from the front grill of the car

Don't have a CANbus ECU in your car

NOTE: Due to Australian vehicles having different down pipe lengths from MY01-MY07

We use 33mm ID runner (others normally use a 36/39/42) to help keep throttle response up

Note: Fits 2003-2007 WRX and 2006-2007 STI Bonnet Scoop Only

Invidia R400 Cat Back Exhaust Fluid Pressure Sensors 100% of the airflow isINVIDIA R400 CAT BACK EXHAUST Invidia's most popular exhaust system. Specifically designed to fill the sound gap between the Q300 and N1 system, the R400 produces a unique, agressive note while minimising harsh cabin noise (particularly at highway speeds). The R400 muffler was designed using years of experience from Invidia's engineers to allow the perfect balance between unrestricted exhaust gas flow and sound dampening. This exhaust system will