Should the secondary catalytic converters be removed on a Porsche Cayenne V8?

The Porsche Cayenne (955, 957, or 958) is a paradox. Under the hood, you have a fabulous V8. But to the ear, it sometimes sounds like an electric sedan. The culprit? The ultra-restrictive exhaust system imposed by regulations, and more specifically, the secondary catalytic converters. The most popular solution among enthusiasts is the "Bypass." But is it risk-free? Let's take a closer look.

What are secondary catalytic converters for? Unlike primary catalytic converters (located just after the exhaust manifolds) which manage emissions and lambda sensors, secondary catalytic converters are located further down under the car, just before the muffler. Their role is to supplement fine filtration, but above all... they act as enormous acoustic barriers.

The 3 advantages of SCART Bypass: Replacing these large catalytic converters with our stainless steel "Bypass" pipes is the number 1 modification on the Cayenne V8. Why?

The unleashed V8 sound: It's night and day. With the pair of valved sport exhausts, you finally get the typical "glug-glug" of an American V8 at idle and a powerful roar under acceleration. It's addictive.

Performance gain : By freeing up the gas flow, the engine breathes better. A gain in torque and a more responsive acceleration are often observed.

Thermal reliability : Catalytic converters store a lot of heat under the car. Removing them helps lower the exhaust system temperature.

What about the vehicle inspection and warning lights? That's a frequently asked question.

Engine Warning Light : On the Cayenne 955 and 957, removing the secondary windings does not light up any warning lights, because the control sensors are located upstream (on the primary windings).

Pollution : The primary catalytic converters do most of the work. If your engine is properly tuned, the vehicle will pass standard emissions tests.

If you find your Cayenne too tame, the secondary bypass and our pair of valved exhausts offer the best value for money. It's a reversible, reliable modification that transforms the driving experience.