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Exhaust› Exhaust Pipes, Systems and Components

Agency Power

3" Cat-Back Exhaust System

Name: 3" Cat-Back Exhaust System
Brand: Agency Power
SKU: AGPAP-GRBS-170S

$679.00

SKU: AGPAP-GRBS-170S

Free Shipping over $200

$100 Minimum Order

Non-Returnable Item

DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Agency Power 3" Catback Exhaust System is designed for the 2015-2021 Subaru WRX and 2015-2018 STI. It features all T304 stainless steel piping with a 3-inch diameter and robotic TIG welding. The system includes a resonator to maintain a boxer engine sound with an exotic tone while preventing cabin drone. The flanges are 1/2 inch thick for a secure fit, and the exhaust uses a high-flow Y-pipe to connect to dual canisters.

Show original supplier description

The Agency Power 3" Catback Exhaust System is engineered to enhance the sound and performance of your 2015-2021 Subaru WRX or 2015-2018 STI. Constructed from premium T304 stainless steel, this system boasts 3-inch diameter piping that is hand-polished and features precise, robotic TIG welding throughout. This catback system utilizes 1/2-inch thick flanges for a robust and secure fitment, integrating seamlessly with factory exhaust hangers. A high-flow Y-pipe efficiently directs exhaust gases to the dual exhaust canisters, featuring a merged collector and 3-inch extensions for optimal flow. Removable exhaust silencers are included for users who prefer a quieter driving experience during daily use. As validated on a Mustang all-wheel-drive dynamometer, this Agency Power catback exhaust system achieved an impressive gain of 17 all-wheel horsepower and 28 ft-lbs of torque. The system is compatible with 2011-2015 WRX STi Sedans and also 2015 WRX/STI models. It is available with either 4-inch dual stainless steel tips or 4-inch dual titanium tips, both featuring the Agency Power logo. This catback exhaust is designed for 2008-2017 Subaru WRX and Subaru WRX STI sedans.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

Brand	Agency Power
Part Number	AGPAP-GRBS-170S
Category	Exhaust

Videos

SUBARU WRX STI Rumbles with Agency Power Catback Exhaust!

Agency Power Subaru WRX STI 02-07 Exhaust

Subaru WRX STI Exhaust Sound With Agency Power Dual 4" Titanium Tip Exhaust System

Subaru WRX STI Hatchback with Agency Power Catback Exhaust | Sound Clip

Bagged Wrx agency power el headers

2011 WRX Quad Blast Pipes w/ Agency Power midpipe

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

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