JOHN ASHLEY EXHAUSTS’S addition to the Vauxhall de-cat manifold is the Z16XEP & Z18XEP 4-1 available in mild steel, stainless steel and our favourite the aluminium white coated manifold. Our de-cat manifolds are a good quality, UK made, durable product, which have been tried and tested for many years. Designed for easy fitment, the 4-1 is an easy bolt on performance product that instantly gives a louder sound and more power.

Replaces the catalytic convertor, which is required for road use, so track use only.

Bolts onto the original system for easy DIY fitment 

Approx 15mins to fit, after the standard manifold has been removed

Technical specification;

4 into 1 de-cat manifold 

Mandrel bent 1 1/2" primaries 

2" collector ideal for a 2" system

Laser cut flanges

lambda boss for probe

We can produce three primariy sizes to order for the Z16XEP & Z18XEP, 1 1/2", 1 5/8" and 1 3/4". We tailor make the exit diameter to suit the system you have; 2", 2 1/4" or 2 1/2".  

For the more serious enthusiast, we can build one off 4-2-1 or 4-1 manifolds to engine builders specifications from £350.

Made in the UK