Valved Exhaust System for Subaru Impreza WRX STI GD 2.5 EJ257 (2006-2007)
Configuration
Subaru Impreza WRX STI GD 2.5 EJ257 Valved Exhaust System (2006-2007)
Valves
Operated by remote control, factory-paired.
Estimated at 0.50 m from the outlet, 45°, 2,000 rpm with a warm engine. Allow ± 2 dB depending on the engine and measuring point. A 3 dB difference is audible in a direct comparison; 10 dB sounds roughly twice as loud.
Configuration guide
Sound intensity with the valves open, on a scale of 0 to 10.
| Configuration | Intensity |
|---|---|
| Decat downpipe + Rog cat-back | 10/10 |
| 100-cell sports catalytic converter + Rog cat-back | 9/10 |
| 200-cell sports catalytic converter + Rog cat-back | 8/10 |
| Rog cat-back only, factory catalytic converter retained | 7/10 |
| Factory exhaust, for comparison | 3/10 |
The Subaru Impreza WRX STI GD 2.5 EJ257 exhaust in detail.
The boxer rumble is one of the most iconic sound signatures in motoring: that syncopated beat of the flat-four, born of unequal-length manifolds, was the soundtrack of rally stages in the early 2000s. On the 2006 and 2007 Impreza WRX STI GD saloon, the 2.5-litre turbocharged EJ257 carries on this heritage with 280 hp and 392 Nm, but its factory exhaust flattens that unique grain.
With the valves open, the Rog valved cat-back gives the boxer back its deep rumble at idle, a gravelly charge as the turbo comes in and crackles on the overrun; with the valves closed, the saloon becomes calm enough for Monday morning. Only the GD saloon with the EJ257 engine is covered here, as the WRX VA and VB take different systems, and we check each Impreza’s VIN before starting manufacturing.
Installation requires no welding, using clamps and gaskets, in about two hours; the original valve control is retained if the STI has it, and failing that the Rog remote, with its box in the boot, operates them.
Between the turbo and the cat-back, the EJ257 keeps a downpipe carrying the catalytic converter, and it is this part that the page offers under the name “Manifold”. On a non-remapped STI, it works on sound and mass, not power; with a suitable map, the published Stage 2 figures reach 390 hp and 520 Nm. An STI GD still driven on the open road will go for the 200-cell downpipe, the only one that keeps emissions control; the 100-cell will be accepted or not depending on the car and the rules in your country, while the decat version is reserved for track use. The single round tip, in the centre of the bumper, comes in 304 stainless steel or titanium, around 40% lighter and finished in brushed, gold or purple.
Subaru Impreza WRX STI GD 2.5 EJ257 exhaust specifications.
| System type | Valved cat-back (valve exhaust), built to your VIN |
|---|---|
| Vehicle and chassis code | Subaru Impreza WRX STI, GD saloon |
| Engine | EJ257, 2.5-litre turbocharged flat-four, 280 hp and 392 Nm |
| Years | 2006-2007 |
| Materials and finishes | 304 stainless steel or titanium; titanium in brushed, gold or purple |
| Valves | Factory valve control if the car has it, otherwise the Rog remote |
| Front section (option) | Downpipe with 200-cell or 100-cell catalytic converter, or decat (“Manifold” option on this page) |
| Fitting | Clamps and gaskets, no welding, about 2 hours |
| Manufacturing and delivery | Made to order, 20 working days, free delivery |
| Warranty | 3 years, parts and workmanship |
Questions about the Subaru Impreza WRX STI GD 2.5 EJ257 exhaust.
Does a five-door Impreza WRX STI GD with the EJ257 engine exist?
This version does not exist: from 2006 to 2007, the EJ257-engined WRX STI was only sold as the GD saloon. The only STI estate of this generation, a Japanese model, had a different engine.
What does an ECU remap bring to the Impreza STI’s EJ257 once the downpipe is fitted?
The map is what turns the freed-up flow into power: the Stage 2 figures published for the EJ257 reach 390 hp and 520 Nm. As long as the factory downpipe stays in place, the standard ECU copes very well with the cat-back.
Can an equipped Impreza STI GD 2.5 be presented at the vehicle inspection?
The configuration to present combines closed valves and an original or 200-cell downpipe: the saloon returns to a level close to stock, catalytic converter active. With the 100-cell, the outcome depends on the car and the country; a decat STI stays on the circuit.
Does the Impreza EJ257’s boxer rumble come from the exhaust system?
It comes mainly from the unequal-length manifolds, upstream; the factory exhaust then dampens it. The Rog cat-back brings it out with the valves open, without touching that part of the engine.
Subaru Impreza WRX STI GD 2.5 EJ257: Does a valved exhaust system drone?
No. With the valves closed, the gases flow through the whole rear silencer and the cabin stays calm at a steady speed. Our Rog exhausts are designed to avoid drone. Learn more: Why our systems stay calm on the motorway.
Subaru Impreza WRX STI GD 2.5 EJ257: straight pipe or resonator?
On this model, two characters at the same price: the straight pipe for the raw sound of your engine, unfiltered, or the resonator for a rounder and slightly softer voice. Either way, the exhaust stays fully sporty. Learn more: Exhaust resonator: what does it do? Straight pipe or resonator, which sound to choose.
Rog expert guide
Subaru Impreza WRX STI GD: bringing back the boxer rumble, the complete guide
The GD Impreza, the one from the Solberg years, is THE collectable Subaru: blobeye and hawkeye examples are snapped up. Its boxer is the soundtrack of an entire era of world rallying: it deserves to be played loud. Here, point...
In detail
Rog Advisor
A question about this exhaust?
Fitment, sound, catalyst, valves, delivery: the answer comes straight away, with your configuration in context.
The Rog Advisor is an automated assistant trained on our product pages and answers. For an important decision, write to us: we confirm by e-mail.
Unsure about your configuration? Talk to us before you order. We know your car. Write to us at contact@rogmotorsport.com: we reply in writing, in English, within 24 hours. Email us
Reviews imported from our previous system and translated from French; verified purchases carry the badge.
Rog presentation film: choosing your vehicle, Standard or Equal Length design, stainless steel or titanium, Z-Pipe, controlled valves, titanium and tip finishes, and support from choosing your configuration through to shipping.
THE Rog CRAFT
Our process.
From the first bend to the last check. The same care at every step.
-
Design
Designed for your vehicle.
Geometry matched to your model, carefully studied bends and precise mounting points. Everything starts with accurate design.
-
Manufacture
Crafted with precision.
Tube bending, part fitting and TIG welding: every joint receives the same care.
-
Finishing
Material, elevated.
The finish reveals the character of the metal. Stainless steel or titanium, depending on the options available for your vehicle.
-
Assembly
Every part in its place.
Components are assembled and adjusted. On valved systems, the mechanism is fitted, set up and tested.
-
Inspection
Check. Then approve.
Geometry, welds, connections and gas flow: the key points are inspected before shipping.
-
Shipping
Ready to join you.
Reinforced packaging protects your exhaust in transit. The final step before giving your vehicle a new voice.
Customer builds
Your videos & photos
The Rog lines fitted on our customers' vehicles, in real conditions.
- Builds
- 500+
- Brands
- 28
- Satisfaction
- 4,9
The journal
News & advice
Best valved exhaust for the Audi RS3 8Y
Which valved exhaust for an Audi RS3 8Y? The options compared (sound, material, valves) and the Rog system made to...
Read the articleBest valved exhaust for the Mercedes-AMG A45 / A45 S W177
Which valved exhaust for a Mercedes-AMG A45 or A45 S W177? The options compared (sound, material, valves) and the Rog...
Read the articleBest valved exhaust for the BMW M2 G87
Which valved exhaust for a BMW M2 G87? The options compared (sound, material, valves) and the Rog system made to...
Read the articleExhaust rules: what changes in 2026 and 2027 (Euro 7, noise cameras, MOT)
Euro 7, new-car noise, noise cameras, MOT and vehicle inspection, and models: what really changes in 2026 and 2027 for...
Read the articleChanging your exhaust: what inspections and approvals cost in 9 countries
What the periodic inspection and the check of a modification cost after changing your exhaust, in 9 European countries: official...
Read the articleIs a cat-back exhaust legal in Ireland? What the NCT checks.
A cat-back leaves your factory cat, sensors and OBD as they are; valves closed, very close to stock, valves open,...
Read the articleSports exhaust (sportsummuti) in Estonia: what the tehnoülevaatus checks.
The sound you choose, a discreet car when it matters: what a Rog valved exhaust gives you in Estonia, how...
Read the articleSports exhaust in Latvia: tehniskā apskate and the CSDD noise limit.
The sound you choose, a discreet car when it matters: what a Rog valved exhaust gives you in Latvia, how...
Read the articleNo article matches this search.
All articles