Every part we sell is a genuine BM Catalysts unit covered by the manufacturer’s warranty against manufacturing defects — 2 years on the standard range, 3 years on premium silicon-carbide (“P”) DPFs. This page explains what that covers, what it doesn’t, and how to make a claim go smoothly. Nothing here affects your statutory rights.
First, three things that protect your claim
- Record the serial number before fitting. Six letters beginning “C” or “D”, pin-stamped on the unit body and printed on the paperwork. It identifies your unit for any warranty query and can be hard to read once installed.
- Fix the cause before fitting the part. Cats and DPFs are usually killed by a vehicle fault. The warranty covers defects in the part — not damage done to it by an unresolved misfire, sensor fault or blocked EGR valve. Our guides to why cats fail and why DPFs block cover the checks.
- Fit it properly. Follow the cat and DPF fitting guides. In particular: a DPF must be fitted by a competent technician with the diagnostic equipment to complete the ECU set-up, no exhaust paste may be used ahead of a cat or DPF, and a part must never be modified to fit — each of these can invalidate the warranty on its own.
What the warranty does not cover
The warranty is against manufacturing defects, so failures caused from outside the part are excluded. The common exclusions, and why:
- Impact damage — dents, scrapes and cracked cores from speed bumps, kerbs or debris.
- Exhaust paste damage — paste used ahead of the unit hardens, breaks up and destroys the core; this is an automatic exclusion. (Silicone-based sealant does not harden the same way and is acceptable where genuinely needed.)
- Oil fouling — oil in the exhaust from a worn engine, failing turbo or leaking seals coats the core and stops it working.
- Plugged or contaminated units — wrong fuel, unsuitable fuel additives, or a vehicle that has been running badly for some time.
- Overheating / melted core — unburned fuel from misfires, ignition faults, leaking injectors or sensor failures superheats the core. A blue-tinted shell is the classic evidence.
- Blocked DPFs — blockage originates upstream of the filter (driving pattern, vehicle fault, failed regeneration), so it is not a defect in the filter itself.
- Emissions failures with high HC — a hydrocarbon reading above 60ppm on the failure report indicates an uncorrected engine fault, and claims for emissions failure aren’t accepted in that case (the MOT test itself allows up to 200ppm, but a healthy engine reads far lower — see MOT emissions failures explained).
- Noise complaints — a cat has some silencing effect but is not a silencer; noise usually indicates excess fuel reaching the unit or an unrelated exhaust fault.
How to claim
- Contact us first — email info@cathive.co.uk with your order number, the part’s serial number, and a description of the problem. Many apparent faults turn out to be fitting or vehicle issues we can help identify quickly.
- For emissions-related claims, include the MOT emissions failure report — the manufacturer requires it before a return can be approved.
- Return for inspection if asked. Where the issue can’t be resolved remotely, the unit is returned through us to BM Catalysts, whose technicians inspect it to establish whether a manufacturing defect is present. We’ll keep you informed at each step.