Plain-English guides to choosing, fitting and looking after catalytic converters, DPFs and related exhaust parts, based on the manufacturer’s own technical guidance and UK law. If you can’t find an answer here, call us on the number above or email info@cathive.co.uk.
Choosing the right part
- What is a catalytic converter and what does it do? How cats work, petrol vs diesel, and why they need replacing.
- What is a DPF and how does regeneration work? Soot traps and regeneration: passive, active and forced.
- Type-approved cats and DPFs: what UK law requires When an approved part is legally required, and how to tell a part qualifies.
- Euro 1 to Euro 6 emissions standards explained The standards, clean-air zone charges, and finding your vehicle’s.
- BM Catalysts part numbers explained What BM11, FK, PP and the H and P suffixes mean, and why serial numbers matter.
Fitting
- What causes a faulty catalytic converter? Diagnose the real cause before you fit, or the new cat dies the same way.
- Blocked DPF? The causes to fix before replacing it The full pre-replacement checklist, from driving patterns to glow plugs and fuel vaporisers.
- How to fit a catalytic converter, step by step Removal and installation, with the warnings that protect your warranty.
- How to replace a DPF: fitting and ECU set-up The mechanical swap and the ECU set-up that makes or breaks the job.
- DPF fitting notes: Vauxhall Zafira, Fords and BMWs Known quirks, including Boxer, Relay and Ducato vans.
Aftercare, MOT & warranty
- Failed your MOT on emissions? What to do next What the CO, HC, lambda and smoke results point to, and what to fix before you buy anything.
- How to look after your DPF and catalytic converter The habits that make these parts last the life of the vehicle.
- Is DPF removal or a DPF delete legal in the UK? Why removal is illegal, how the MOT catches it, and what to do instead.
- Catalytic converter and DPF warranty: how to claim What’s covered, what isn’t and why, and how to make a claim go smoothly.
Shop by part type
Catalytic converters · DPFs · Catalytic converter and DPF units · Catalytic converter and GPF units · SCR and DPF units · Pressure pipes · Exhaust pipes · Fitting kits · Find your vehicle
Ready to find your part? Start with the part finder, or search any Klarius, Bosal, Walker, EEC or OE part number directly from the search box.
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