Milltek Secondary Catalyst Bypass (Fits to OE System Only) - Porsche 958 Cayenne S 4.8 V8 (Non-Turbo) - SSXPO204

The Milltek Secondary Catalyst Bypass is engineered for Porsche 958 Cayenne S non-turbo models. This bolt-on component bypasses the secondary catalyst, unlocking mid-range performance and refining exhaust tone without modification to the OE system.

Direct factory fitment using OEM hangers and mounting points, no cutting or modification required. Hand-finished T304L stainless steel construction with CNC-formed internals engineered to eliminate secondary catalyst resonance points while maintaining clean emissions under standard driving.

Bolt-on installation. Fits 958 Cayenne S (M48.02 4.8 V8 non-turbo) exclusively. Dyno-tested for repeatable gains in mid-range response and acoustic character refinement.

Pre-facelift vs facelift, explained: The 958 Cayenne S used the 4.8 V8 on the pre-facelift 958.1 only, sold through the 2014 model year. From 2015 the facelift 958.2 Cayenne S switched to a 3.6 twin-turbo V6, so this V8 part does not fit facelift cars. If your Cayenne S is a 2014 model, confirm it has the 4.8 V8 before ordering.

Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Specifications

• Pipe diameter: 70mm (2.76")
• Fitting time: 1 to 2 hours, including removing the factory system
• Off-road / competition use only. Not legal for use on public roads in the US.

Fitment

• Porsche > Cayenne > 958 S 4.8 V8 (Non Turbo) Models > 2010 to 2014

• Free US shipping on orders over $250.
• Free pickup at our Dallas shop, usually ready within 24 hours.
• Unused parts can be returned within 30 days. Tunes, opened electronics, merch and installed parts are final sale.
• Want it installed? Book the install at thegbmotors.com.

Full details are on our shipping and returns page.