Exhaust Header for 1997-2005 Subaru Impreza RS TS Outback/Outback Sport丨Legacy GT 2.5L Racing NON-turbo

Exhaust Headers for 1997-2005 Subaru Impreza RS/TS/Outback & Legacy GT 2.5L Engines – Racing NON-Turbo

Sharing from @TheSubieSanctuary

Give your compatible Subaru a stronger exhaust foundation with an unequal-length header built for freer flow, a deeper boxer tone, and future naturally aspirated performance upgrades. This Flashark stainless steel racing header is designed for the listed 1997-2005 Subaru Impreza RS, Impreza TS, Outback/Outback Sport, and Legacy GT 2.5L non-turbo applications.

The unequal-length tube layout changes the way exhaust pulses reach the collector, helping produce the uneven, low-pitched sound many Subaru owners want from an older naturally aspirated build. It can also replace a corroded, cracked, or restrictive factory manifold, but fitment should be confirmed by year, model, body style, engine configuration, oil-cooler setup, flange layout, and downstream exhaust connection before ordering.

Specifications

Key Features

• Unequal-length tube routing: Produces a deeper and more uneven boxer exhaust pulse than a typical factory manifold.
• Stainless steel construction: Better suited to exhaust heat and road exposure than an untreated mild-steel component.
• Mirror-polished exterior: Provides a clean finished appearance before normal heat cycling and discoloration occur.
• Individual primary tubing: Replaces the stock-style manifold path with a tubular header arrangement.
• Factory-style mounting approach: Designed around the listed applications, while allowing for normal inspection and adjustment on older vehicles.
• Installation components shown: Product photos show matching gaskets and mounting bolts with the header assembly.
• Budget-conscious upgrade path: Suitable for an owner prioritizing sound, manifold replacement, and basic naturally aspirated exhaust improvements.

What This Header Can—and Cannot—Fix

When It May Help

A replacement header can help when the original manifold is cracked, heavily corroded, restricted, or leaking at a flange. It can also change the exhaust pulse character and give the naturally aspirated boxer engine a deeper, more aggressive note.

When an exhaust tick is caused by a damaged manifold or failed manifold gasket, replacing the affected parts and restoring a flat, sealed connection may solve the noise. The cylinder-head sealing surfaces, studs, downstream flange, and gaskets must still be in usable condition.

What It Will Not Repair

• An internal engine knock, piston slap, valvetrain noise, or rod-bearing noise.
• A misfire caused by ignition, fuel, compression, or sensor problems.
• Broken cylinder-head studs or damaged threads unless they are repaired separately.
• A failed catalytic converter, worn O2 sensor, or exhaust leak farther downstream.
• A warped cylinder-head sealing surface or badly misaligned aftermarket exhaust.
• A Check Engine Light caused by an existing engine or emissions-system fault.

UEL Header vs. the Factory Manifold

For this Subaru application, the useful comparison is not the usual truck-style “long tube versus shorty” decision. The main choice is between the factory manifold layout and this unequal-length tubular header.

Expected Sound and Performance

The most noticeable change should be the exhaust note. An unequal-length header alters the timing of the exhaust pulses reaching the collector, producing the uneven boxer rhythm many Subaru owners are looking for. The final volume still depends heavily on the catalytic converter, resonator, muffler, pipe diameter, and any existing exhaust modifications.

On an otherwise stock naturally aspirated 2.5L engine, a realistic header-only result can range from no clearly measurable wheel-horsepower increase to roughly 5-10 horsepower on a properly running vehicle. Engine condition, exhaust restriction, intake setup, ECU calibration, altitude, fuel, and the test method all affect the result.

This range is not a dyno guarantee. Some owners may notice throttle response and mid-range feel more than a large peak-power change. A matching exhaust and appropriate ECU calibration may help a modified setup make better use of the additional flow, but a tune should not be treated as a substitute for correct installation or leak repair.

No fuel-economy increase is guaranteed. Driving style, exhaust configuration, engine condition, and ECU behavior have a much larger effect on fuel consumption than the header alone.

Who This Header Is For

• Owners of a listed 2.5L non-turbo Subaru who want a deeper unequal-length boxer exhaust note.
• Drivers replacing a corroded, cracked, leaking, or damaged factory manifold after confirming the leak source.
• Impreza RS, Impreza TS, Outback Sport, and listed Legacy GT owners building a naturally aspirated street, autocross, or track-focused exhaust setup.
• Buyers who are comfortable checking engine, body style, oil-cooler configuration, exhaust flanges, and O2 sensor locations before ordering.
• DIY installers with proper lifting equipment, penetrating oil, hand tools, an O2 sensor socket, and experience working around old exhaust hardware.
• Owners working with an exhaust shop when the vehicle has heavy rust, broken studs, a custom mid-pipe, or previous exhaust modifications.

Shipping, Warranty & Customer Support

• Estimated Delivery: Most orders are delivered within 7-9 business days after shipment, depending on warehouse availability and destination.
• 1-Year Warranty: This product is backed by a 1-year warranty against manufacturing defects.
• Returns & Fitment Support: Please confirm your vehicle year, model, engine, and drivetrain before ordering. If you are unsure about fitment, contact customer support before purchase.
• Customer Support: Our support team can help with basic fitment questions, order issues, and warranty-related support.