Cobb Tuning GESI Catted Downpipe 2002-2007 WRX / STi

The COBB Tuning GESi Catted 3″ Downpipe begins with a CAD designed cast bellmouth that smoothly blends air exiting the turbocharger’s turbine housing. Minimizing turbulence when exhaust gasses from the wastegate join into those flowing through the turbine helps to prevent excessive back-pressure. The cast housing is capped off with a COBB logo and auxiliary O2 bung for those wanting to install a wideband sensor early in the exhaust path.

A welded bracket utilizes the factory hard mount near the transmission reducing stress on the turbocharger mounting bolts and studs.

Corrosion resistant and mandrel bent 3″ 304 Stainless Steel tubing carries exhaust gasses down stream into a COBB-exclusive GESi 300 cell high flow catalytic converter. A second O2 bung is located directly after the catalytic converter and is to be used by the OEM Rear O2 sensor.

A CAD designed, cast 304 stainless steel, flange finishes off the tail section of the downpipe. The reinforced cast flange is less susceptible to warp during assembly. A stainless adapter flange and included MLS gasket allows direct fit with the factory exhaust or COBB Cat-Back Exhaust utilizing the OEM donut gasket. Included COBB proprietary shoulder nuts allow installation of the factory spring bolts without fuss.

Note that this downpipe will require custom ECU tuning.