Catback Exhaust System for 2015-2021 Subaru WRX / STI, 4-inch Quad Muffler Tips, N1 Style Burnt Tip

• 2015-2021 Subaru WRX

• 2015-2021 Subaru WRX STI

Flashark 2015-2021 Subaru WRX / STI Catback Exhaust FAQ

Q1: Will this catback exhaust fit both my 2015 WRX and a 2021 STI?

A1: Yes! This Flashark catback exhaust is precisely engineered as a direct bolt-on upgrade for the entire 2015-2021 VA chassis generation. Whether you are driving a 2015 Subaru WRX base with the FA20 2.0L turbo or a 2021 STI with the EJ25, the exhaust routing and hangar locations match up perfectly. It covers all years in between, including highly searched models like the 2017 WRX catback exhaust and 2020 WRX exhaust system.

Q2: How much louder is it than stock? Will I get that classic Subaru rumble?

A2: It is significantly more aggressive than the restrictive stock WRX exhaust. If you want a loud exhaust for Subaru WRX, the N1 style straight-through design delivers. On an STI, it fully unlocks that legendary unequal-length (UEL) header "boxer rumble." On the WRX, it provides a crisp, deep, and sporty tone. If you are worried about it being too loud for daily driving, we highly recommend choosing the "Burnt Catback w/ Muffler" option for a refined, drone-free tone, rather than the pure muffler-delete version.

Q3: Will this Subaru WRX performance exhaust actually add horsepower?

A3: Absolutely. The factory exhaust uses heavily baffled mufflers and crushed pipe sections that create backpressure. By upgrading to a full catback exhaust with smooth, 3-inch mandrel-bent piping, you are significantly improving exhaust gas velocity. This reduction in backpressure allows your turbocharged engine to spool faster, resulting in better throttle response and noticeable mid-range power gains.

Q4: What is the difference between a full WRX cat back exhaust and an axle-back exhaust?

A4: A 2015 WRX axle back exhaust only replaces the rear mufflers and tips, which changes the sound but does very little for performance. A catback exhaust system replaces everything from the catalytic converter backward, including the restrictive factory mid-pipe. If you want the best exhaust for WRX performance, a full 3-inch catback is the definitive choice for flow and horsepower potential.

Q5: Do I need a professional tune after installing this WRX aftermarket exhaust?

A5: No ECU tune is required! Because a cat back exhaust bolts on after the primary and secondary catalytic converters, it does not alter the mass airflow sensor readings or the air/fuel ratio enough to require a tune. You can safely bolt on this Subaru WRX exhaust upgrade and drive immediately without throwing a Check Engine Light (CEL).

Q6: Are the 4-inch quad muffler tips authentic, or are they just fake exhaust tips?

A6: These are massive, high-quality 4-inch quad outlet tips made from premium stainless steel, featuring an authentic N1-style burnt titanium-look finish. Say goodbye to tiny, unimpressive stock tips or fake exhaust tips. These 4-inch quad tips perfectly fill out the factory rear bumper cutouts, giving your VA WRX or STI a much more aggressive, motorsport-inspired rear stance.

Q7: Can I install this 2015-2021 WRX exhaust system myself at home?

A7: Yes! As experienced tuning technicians, we designed this to be a 100% direct bolt-on Subaru WRX STI exhaust system. There is no cutting or welding required. With a basic set of metric sockets, wrenches, and safe jack stands, a weekend DIY enthusiast can install this in a driveway in about 1 to 2 hours. All necessary CNC-machined flanges, bolts, and gaskets are included in the box.

Q8: Will this exhaust rust over time?

A8: We build our Flashark catback exhausts using ISO9001:2000 certified stainless steel with a high-quality mirror polish. This provides excellent rust and corrosion resistance, far superior to standard mild steel exhausts. To keep it looking pristine, especially the burnt tips, we recommend giving it a quick wipe-down during your regular car washes.

Q9: Why are Flashark reviews so positive compared to other brands?

A9: If you look at Flashark catback exhaust reviews or Flashark racing reviews, you'll see a consistent theme: unbeatable value. We provide the same TIG-welded, CNC-flanged, 3-inch stainless steel construction as exhaust systems that cost twice as much. You get premium track-tested performance, incredible sound, and perfect fitment without the "JDM brand tax."

Q10: Does this STI exhaust fit on WRX without modification?

A10: Yes. One of the greatest things about the 2015-2021 chassis is that a Subaru exhaust STI model shares the exact same mid-pipe and rear muffler hanger locations as the FA20 WRX. This kit is universally compatible across both models out of the box, meaning an STI exhaust on WRX is a seamless, perfect fit.

Q11: Will this affect my vehicle's emissions status?

A11: No. A subaru cat back exhaust only replaces the piping after the factory catalytic converters. Because you are leaving the stock cats untouched in the J-pipe/downpipe, your vehicle remains completely emissions-compliant in most regions. It’s the perfect way to get a loud exhaust for Subaru WRX without failing smog checks.

Q12: Which version should I buy: "Burnt Catback" or "Burnt Catback w/ Muffler"?

A12: It depends on your driving style. If you want the absolute loudest WRX exhaust with an aggressive, raw, race-inspired sound that pops and bangs, choose the straight-pipe "Burnt Catback" (muffler delete). If this is your daily driver and you want a deep, sporty tone that won't wake up the whole neighborhood or drone heavily on the highway, select the "Burnt Catback w/ Muffler" for a perfect balance of performance and comfort.