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GP SPORT Exas High-flow Power Catalyser for Mazda RX8 (Series 1 & 2, 2003-2012)

Swap the restrictive factory cat for a freer-flowing performance catalytic converter that retains emissions equipment across the full 2003-2012 RX8 range.

$1,650 inc GST

The Mazda RX8 high flow cat from GP SPORT’s Exas range is a purpose-built performance catalytic converter for Series 1 and Series 2 owners. It replaces the stock unit with a less restrictive design, freeing exhaust flow without discarding emissions equipment entirely. That distinction matters: a high-flow cat keeps the exhaust compliant in spirit. A straight decat pipe does not.

Mazda RX8 High Flow Cat Features

  • Purpose-built fitment covers every RX8 produced from 2003 to 2012, suiting both Series 1 and Series 2 without modification.
  • The high-flow cell design reduces exhaust backpressure at this section of the system. This lets the rotary engine breathe more freely toward the redline.
  • Retaining a catalytic converter keeps you on the right side of emissions regulations, unlike a full decat setup.
  • GP SPORT is a recognised Japanese performance brand. The Exas name sits within their exhaust product line as a dedicated power catalyser, not a universal fitment part.
  • Finally, pairing this with a matched cat-back system gives the full exhaust path a coherent, low-restriction flow from manifold to tip.

For rotary enthusiasts, the clearest reward comes at higher revs. The Renesis responds well to reduced exhaust restriction. Swapping to a freer-flowing cat is one of the most accessible exhaust upgrades that still leaves emissions hardware in place. Expect a sharper, more defined exhaust note as flow improves through this section.

The natural companion to this Mazda RX8 high flow cat is the HKS Hi-Power Cat-Back Exhaust with Titanium Tip, which extends the low-restriction philosophy from the cat to the rear of the system. For more on the Exas catalyser range, visit the GP SPORT official website.

Additional information

SKU GP-CAT-S1S2 Category Types , Brand:

Related RX8 Upgrades

This GP SPORT Exas High-flow Power Catalyser for Mazda RX8 (Series 1 & 2, 2003-2012) is one of the best Mazda RX-8 upgrades you can make to your Mazda Rx8 Series 1 Parts Australia or Series 2 (2009-2012). GP SPORT Exas High-flow Power Catalyser for Mazda RX8 (Series 1 & 2, 2003-2012) are among the top Aftermarket mods you can buy from GP SPORT for owners who want better performance and reliability from their RX8. If you are looking for GP SPORT Exas High-flow Power Catalyser for Mazda RX8 (Series 1 & 2, 2003-2012) for sale in Brisbane (QLD), Sydney (NSW), Melbourne (VIC), Canberra (ACT), Adelaide (SA), Darwin (NT) or Perth (WA), you’ll find high-quality Japanese Exhaust upgrades at RX8 Upgrades.

Frequently Asked Questions

Does the GP SPORT Exas high-flow catalyser fit both Series 1 and Series 2 RX8 models?

Yes, the GP SPORT Exas Power Catalyser covers the full RX8 range, fitting both Series 1 (2003-2008) and Series 2 (2009-2012) models. You don't need to source different parts for each series.

What is the difference between a high-flow catalyser and a standard catalytic converter?

A high-flow catalyser uses a less restrictive core than a factory unit, allowing exhaust gases to pass through more freely while retaining catalytic converter function. For a rotary engine that breathes through every revolution without a traditional piston intake cycle, reducing exhaust restriction is a meaningful part of an exhaust build.

Does this catalyser keep the RX8 emissions equipment in place?

Yes, the GP SPORT Exas is a catalytic converter replacement, not a decat pipe, so your emissions equipment remains functional. This avoids the drone and emissions compliance issues that can come with a full decat setup.

Will this high-flow cat work with an aftermarket cat-back exhaust system?

The GP SPORT Exas is designed as a purpose-specific RX8 component and is well suited to pairing with an aftermarket cat-back system. Matching a high-flow catalyser with a free-flowing cat-back addresses restriction at both ends of the mid-exhaust section for a more cohesive build.

Is professional installation recommended for this catalyser?

Catalytic converter replacement involves exhaust system removal and, depending on your setup, may require a tune or at minimum an oxygen sensor reset. Professional fitting is recommended to ensure correct sealing and to address any remapping requirements.

Will I need an ECU remap after fitting the GP SPORT Exas high-flow catalyser?

A remap is not always mandatory when fitting a high-flow catalyser in place of a stock unit, but it is often recommended to take full advantage of the reduced exhaust restriction. Consult a rotary-experienced tuner to assess whether your current tune remains appropriate.

Why choose a named brand catalyser like the GP SPORT Exas over a generic high-flow cat?

The GP SPORT Exas is a product designed specifically for the RX8 exhaust system rather than a universal fitment unit adapted to suit. A purpose-built component from an established Japanese performance brand offers more confidence in fit quality and consistency than an unbranded generic alternative.