String Theory Garage will be closed to the public from Wednesday, 29th July to Thursday, 6th August for our annual shutdown.
If you need to get in touch, please leave us a voicemail or send an email. Our team will happily get back to you when we return on Friday, 7th August.
Shopping online? Don't worry! Our online store will remain active! We hope to ship orders placed for in-stock items as normal during the shutdown. Anything else will be dealt with upon our return.
Thank you for your understanding, String Theory Garage Team
Improve the exhaust flow and acoustic character of your Porsche Cayenne 958 S (4.8L V8, Non-Turbo) with this Milltek Sport Secondary Cat Bypass System. Replacing the factory secondary catalytic converters with straight-through 304L stainless steel bypass pipes, this system reduces exhaust restriction — delivering improved flow and a more characterful V8 exhaust note, particularly at higher engine speeds.
For off-road or track use in jurisdictions where secondary cat removal is permitted. A straightforward bolt-on replacement. Made in the UK by Milltek Sport.
Fitment: Porsche Cayenne 958 S (4.8L V8, Non-Turbo)
SKU: SSXPO204
Secondary cat bypass — check local regulations before use on public roads