Invidia Catted J-Pipe & Downpipe With Wide Band & High Flow Cat - 2015-2021 Subaru WRX (Manual Transmission Only)

The Complete J-Pipe and Downpipe Solution for the VA WRX/STI

The Invidia Catted J-Pipe and Downpipe with Wideband Bung and High Flow Cat for the 2015-2021 Subaru WRX / STI (manual transmission only) replaces both the J-pipe and the downpipe with a single high-flow system that retains catalytic converter compliance while dramatically outflowing the restrictive factory units. A tune is required after installation.

High-Flow Cat: Compliant and Free-Flowing

The high-flow catalytic converter included in this downpipe flows significantly more exhaust gas than the factory unit while maintaining catalytic function. For builds requiring a street-legal exhaust, the catted downpipe provides the majority of the performance benefit of a catless unit while keeping the vehicle compliant in most jurisdictions outside California.

Wideband Bung Included — Ready for Tuning

The wideband O2 bung allows installation of an aftermarket wideband sensor alongside the factory narrowband — essential for the tuner who needs accurate AFR data. A professional tune is mandatory with this installation. Do not run on the stock ECU calibration.

Key Features

• Platform: 2015-2021 Subaru WRX / STI (manual transmission only)
• 304 stainless steel, 3-inch mandrel-bent piping
• High-flow catalytic converter — emissions compliant (not CARB legal)
• Extra O2 bung for wideband sensor
• Bolt-in at factory turbocharger outlet flange
• Compatible with OEM and aftermarket cat-back exhaust systems
• TUNE REQUIRED — do not run on stock ECU calibration

Fitment Notes

• Platform: 2015-2021 Subaru WRX / STI
• Manual transmission only
• TUNE REQUIRED after installation
• NOT CARB legal — cannot ship to California
• Wideband O2 bung included

Straight From Subispeed

The Invidia catted downpipe is the correct first major exhaust upgrade on the VA WRX/STI for owners who need to keep the car street-legal. The high-flow cat outflows the stock unit significantly while maintaining emissions compliance in most states outside California. A tune is not optional with this installation — running any aftermarket downpipe on the stock ECU calibration is a reliability concern, not just a performance one.

What's Included

• Invidia Catted J-Pipe and Downpipe
• High-flow catalytic converter
• New exhaust gasket and hardware

About Invidia

Invidia is a Taiwanese performance exhaust manufacturer with a strong following in the Subaru, Mitsubishi, and Japanese sports car communities. Their catalog covers cat-back exhausts, downpipes, headers, manifolds, and full exhaust systems built around SUS304 stainless steel construction with CNC-machined flanges and direct OEM fitment. Invidia exhausts are among the most widely installed aftermarket systems on Subaru platforms globally — well-documented, well-supported, and proven across thousands of street and track builds. Subispeed carries the full Invidia lineup because their combination of quality construction, fitment accuracy, and range of tip and finish options makes them the exhaust brand we recommend to Subaru owners at nearly every power level.