MRT

The best MRT parts for the WRX and WRX STI are its Street Race exhaust systems: the Street Race J-pipe for the 2015-2021 WRX, the Extreme cat-back listed for the 2015-2021 WRX and WRX STI for use with the MRT J-pipe only, and the Street Race turbo-back systems for the 2015-2021 WRX, the 2011-2014 WRX and 2008-2014 WRX STI hatchback, and the 2011-2014 WRX and WRX STI sedan. MRT sells matched exhaust sections and complete turbo-backs rather than universal mufflers, so each listing is tied to a specific generation and body style. Check your year and model, including hatchback versus sedan, before ordering.

An exhaust is sold in sections. A J-pipe leaves the turbo, a cat-back runs from the catalytic converter to the tips, and a turbo-back replaces both in one system. The Extreme cat-back for the 2015-2021 WRX and WRX STI is listed for use with the MRT J-pipe only, so it is a partner piece for that J-pipe, not a stand-alone cat-back.

MRT, listed here through its Street Race line, builds its Subaru range around complete, matched systems for turbo cars. The same Street Race name covers the 2015-2021 WRX J-pipe and turbo-back, and separate turbo-backs split by body style for the earlier cars: a Street Race DMS turbo-back for the 2011-2014 WRX and 2008-2014 WRX STI hatchback, and a Street Race turbo-back for the 2011-2014 WRX and WRX STI sedan. Pick the system drawn for your exact car instead of adapting a near-fit exhaust. The Street Race turbo-back for the 2015-2021 WRX is the complete-system option for the newer car.

Invidia is the exhaust brand most WRX and WRX STI buyers cross-shop, known for model-specific cat-backs and downpipes across Subaru generations. GrimmSpeed is a Subaru specialist known for exhaust and engine parts engineered around turbo Subaru platforms, including J-pipe and downpipe work. COBB Tuning covers the tuning side that often pairs with exhaust changes, alongside its own hardware. Compare the wider catback exhaust systems range, see the Street Race turbo-back for the sedan, and read comparing different cat-back exhausts for the 2015 and newer WRX and WRX STI before choosing.

Will the MRT Extreme cat-back fit my stock J-pipe?

The listing states the Extreme cat-back is for use with the MRT J-pipe only. Plan on pairing it with the MRT J-pipe listed for the 2015-2021 WRX rather than assuming it bolts to a factory or other-brand front section.

What is the difference between the turbo-back and the cat-back listings?

A turbo-back, such as the Street Race turbo-backs for the 2015-2021 WRX and the 2011-2014 cars, replaces the exhaust from the turbo back in one system. The cat-back listing here replaces only the rear section, and it is tied to the MRT J-pipe.

Does hatchback versus sedan matter?

Yes. MRT lists a separate Street Race DMS turbo-back for the 2011-2014 WRX and 2008-2014 WRX STI hatchback and a separate turbo-back for the 2011-2014 WRX and WRX STI sedan. Match the body style in the listing title to your car.

Will a turbo-back or J-pipe require a tune?

It can, because changing the exhaust section that leaves the turbo changes how the engine breathes and is monitored. Confirm the tuning requirements for your exact year, model, and system before installing, and check your year and model first.