TX4 Taxi Aftermarket Exhaust Parts
Our premium aftermarket exhaust range dedicated specifically to Euro 5 TX4 models
The TX4 aftermarket range includes:
- Diesel Particulate Filters (DPF®)
- Diesel Oxidation Catalysts (DOC)
- Exhaust Silencers
Fully certified replacement components engineered to OEM-level quality.
Our new premium aftermarket exhaust range dedicated specifically to Euro 5 TX4 models, reinforces our commitment to quality, compliance, and durability in the UK taxi sector.
HJS DPF, DOC and silencer assemblies all meet the approvals and E-mark certification to meet UK regulatory requirements. Notably, the HJS DPF is manufactured using high-grade silicon carbide substrate technology — a material recognised for its superior thermal resistance, filtration efficiency and long-term reliability compared with lower-specification alternatives available in the marketplace.
Each component has been developed to ensure long service life, consistent emissions performance and seamless installation.
Designed to Fill a Critical Gap in the Market
During the development of our TX4 Euro 6 emissions upgrade programme in London, HJS identified a major issue in the UK aftermarket:
There were no replacement DPFs, DOCs or silencers available for the Euro 5 TX4 platform.
To solve this, HJS invested in designing and manufacturing a complete solution from the ground up.
Prototypes were first developed and tested at HJS UK, before being transferred to our headquarters in Germany for advanced prototyping, precision flow analysis and durability testing.
Following extensive testing, the components achieved full homologation and E-mark certification, ensuring compliance with UK regulations.
The HJS DPF is manufactured using high-grade silicon carbide substrate technology, providing:
- Superior thermal resistance
- Exceptional filtration efficiency
- Long-term durability in demanding taxi operations
This advanced material significantly outperforms lower-grade alternatives commonly found in the aftermarket.
Supporting Euro 6 Retrofit Upgrades
These components also support the continuation of Euro 6 retrofit upgrades for TX4 taxis operating in London.
Under the requirements set by Transport for London, Euro 5 diesel taxis undergoing conversion must replace both the DOC and DPF to achieve compliance.
Trusted Exhaust and Emissions Expertise
With certified components, OEM-level manufacturing standards and a dedicated focus on the TX4 platform, HJS continues to strengthen its position as a trusted emissions and exhaust partner for the UK taxi industry.
For more information about TX4 aftermarket exhaust parts or Euro 6 emission upgrades, contact our UK team!