Product Specifications
Choose the Exhaust Section That Matches Your Build
This 2015–2021 Subaru WRX and WRX STI exhaust family gives you two different upgrade paths: an axle-back configuration for the rear section, or a cat-back configuration that replaces more of the downstream exhaust. Select by SKU before ordering because pipe size, tip size, resonator layout, muffler layout, finish, and package contents are not the same across the four options.
Start with product type: Choose FLES08144 only when you need the axle-back configuration. Choose FLES08141, FLES08142, or FLES08143 when you need a cat-back configuration.
Match the vehicle: This product family is listed for 2015–2021 Subaru WRX and WRX STI AWD four-door applications. Match the model, engine, and selected SKU before ordering.
Match the hardware: Package contents differ by SKU. Review the included-hardware row before installation.
Account for an existing exhaust setup: A non-factory downpipe, intermediate connection, or other exhaust modification can change interface requirements and final alignment. Contact customer support if your vehicle is not using the factory connection layout.
Specifications
| SKU / Option | Product type | Pipe diameter | Tips / Exit | Muffler / Resonator | Material / Tip finish |
|---|---|---|---|---|---|
|
FLES08144 Axle Back Burnt Tips |
Axle-back | 2.36 in OD | Four 3.5 in tips Dual rear exit |
No muffler No resonator |
201 stainless steel Burnt tips |
|
FLES08142 Polished Catback |
Cat-back | 3 in + 2.36 in OD | Four 4 in tips Dual rear exit |
No muffler One resonator |
201 stainless steel Polished tips |
|
FLES08143 Burnt Catback |
Cat-back | 2.36 in OD | Four 4 in tips Dual rear exit |
No muffler No resonator |
201 stainless steel Burnt tips |
|
FLES08141 Burnt Catback w/ Muffler |
Cat-back | 3 in + 2.36 in OD | Four 4 in tips Dual rear exit |
Four mufflers One resonator |
201 stainless steel Burnt tips |
Included Hardware
- FLES08144: Gaskets, bolts, and nuts.
- FLES08141, FLES08142, and FLES08143: Gaskets, bolts, nuts, and clamps.
Package contents vary by selected configuration. Select the required SKU before ordering, compare the received parts with the selected configuration, and contact customer support before installation if parts do not match.
Where Each Option Sits in the Exhaust System
The axle-back option changes the rear section and is not a full cat-back exhaust. The cat-back options replace a larger downstream section and use different pipe, resonator, and muffler layouts. None of these options should be selected as a header, downpipe, catalytic converter, or test-pipe replacement.
How to Choose
- Choose axle-back or cat-back based on the section you intend to replace.
- Match the SKU to the required muffler and resonator layout.
- Match the 3.5-inch or 4-inch tip size and burnt or polished finish.
- Review the included hardware for that SKU.
- Check the vehicle and existing exhaust connection before installation.
Sound & Cabin Resonance
Muffler and resonator layouts differ across the four configurations, so one sound description cannot represent every SKU. Final volume, tone, and cabin resonance also depend on the engine, transmission, cruising speed and RPM, and other exhaust modifications. Choose by confirmed hardware layout rather than a universal loudness label.
Drivers who need a specific cold-start level, highway-cruise result, or drone threshold should review a sound sample recorded on the same vehicle and exhaust configuration before choosing a SKU.
Installation & Post-Installation Checks
These configurations are listed as bolt-on installations with no cutting. Before starting, match the SKU, pipe layout, gaskets, fasteners, clamps, and vehicle connection. An altered exhaust connection can require a different installation plan.
- Support the exhaust before loosening the factory hardware.
- Position the full system before final tightening so the hangers and tips can be aligned without preload.
- After installation, check every joint for leaks.
- Check clearance around the body, heat shields, suspension, and rear bumper.
- Check hanger position, tip alignment, and bumper clearance.
- Stop driving and inspect the installation if there is contact, knocking, abnormal vibration, overheating, an unexplained warning light, or an exhaust leak.
Emissions, Road Use & Vehicle Warranty
Do not remove, bypass, or relocate a catalytic converter, oxygen sensor, or other emissions-control component during installation. Road-use, inspection, and noise requirements vary by state and locality. Product coverage and a vehicle manufacturer's warranty are separate matters; warranty decisions can depend on the cause of a specific failure.
Who Should Not Buy
- Do not order if your vehicle is outside the listed 2015–2021 WRX or WRX STI applications.
- Do not order the axle-back SKU when you need a full cat-back configuration.
- Do not order a cat-back SKU when you only intend to replace the rear axle-back section.
- Do not order by sound label alone when you require a measured cold-start, cruise, or cabin-resonance result.
- Do not proceed with installation if the selected parts do not match the vehicle connection or the SKU package.
Shipping & Returns
Free U.S. Shipping: Orders are typically processed within 1–2 business days and delivered within 7–9 business days. Additional charges may apply to remote areas.
30-Day Returns: Unopened and unused items in their original packaging may be returned within 30 days of receipt. Return shipping is covered for verified quality issues.
Worry-Free Delivery: Optional protection against eligible loss, theft, delay, or transit damage is available at checkout.
