The HKS WRX & STi Downpipe is designed as a simple, cheap solution for making power. The HKS WRX downpipe will eliminate both catalytic converters on your 2002-2007 Subaru WRX or 2004-2007 STi, and features 3in piping for optimal flow. While the HKS downpipe will improve performance, we do not reccomend it for anything other than a stock turbo, due to the flat-plate design that does creates wastegate turbulence.
Because the HKS downpipe eliminates both catalytic converters, it is not emissions legal and will trigger an emissions Check Engine Light (CEL) — while it is not harmful, we reccomend the Cobb Accessport to properly tune the vehicle for the downpipe and eliminate the CEL. The HKS WRX & STi downpipe does help reduce boost spiking in 2.5L Subaru cars because of the reduced wastegate flow. This downpipe is full 3in with a flat rear flange, so we recommend an aftermarket 3in catback exhaust for proper fitment.
Part Number: 33006-BF001