CAT cleaning that gets your vehicles back to work
On-car or off-car cleaningOff-car from £250 (exc VAT)Off-car prices include collection and return.
Mobile or factory (off-car) catalytic converter cleaning for vans, HGVs, buses, coaches, plant and cars – petrol and diesel. A comparable result to a new unit, at a fraction of the cost.
Trade Enquiry
Talk to our commercial team0333 366 2018or tell us about your vehicles here for a quotationClean first where suitable. Replace only where necessary.
Catalytic converters on petrol and diesel vehicles block with carbon deposits in the same way as DPFs. Cleaning is often all that’s needed – it restores exhaust flow, improves engine efficiency and resolves the P0420 efficiency code when deposits are the cause, helping vehicles pass emissions tests.
CAT trade pricing
Cleaning costs a fraction of a new converter, with a comparable result – and no wait for parts. Prices depend on the vehicle and whether we clean on-car or off-car, with Trade Account rates available. Send us the vehicle details for a fixed quotation.
Get trade pricingHow fast can you get to us?
On-car: our engineer is usually with you next day, sometimes even same-day, and the clean takes 1–2 hours at your depot, yard or customer site. Off-car: we collect by courier and clean in 1–2 days.
Check availabilityCheck engine light or P0420?
A blocked converter raises back pressure, cuts power and economy, and can push the vehicle into limp mode. Left too long, the heat can melt the substrate – then cleaning is no longer an option. Do not wait for limp mode.
Call the business hotlineThe UK’s DPF specialists
Every job is done by our own trained engineers, never subcontracted. Each vehicle gets diagnostics before and after cleaning, the reports are yours to keep, and every clean is backed by a 30-day warranty.
Trustpilot
Symptoms of a blocked CAT
These symptoms can point to engine damage and a future MOT failure. Spot them early and a clean is usually all that’s needed. If you want the background, read how a catalytic converter works.
Watch out for:
- Power loss – struggling to accelerate under load
- A “rotten egg” sulphur smell from the exhaust
- Check engine light, often code P0420
- Excessive heat from under the floor
- Falling fuel economy
- Rattling on start-up or over bumps*
*A rattle usually means the honeycomb has broken up – that normally needs a replacement rather than a clean.
Cleaning restores:
- Free exhaust flow and lower back pressure
- Engine power and efficiency
- Emissions performance for the MOT
- Fuel economy
- A comparable result to a new unit
- Uptime – no wait for a replacement part
On-car or off-car – whichever suits the job
On-car CAT cleaning
Available for most vehicles, petrol and diesel. We use specialist chemical cleaning equipment to dislodge the blockage without damaging the converter’s internal structure – a huge saving against a new unit, with a comparable result.
- Our engineer arrives – usually next day, sometimes even same-day
- The job is done at your depot, yard or customer site
- Cleaning takes 1–2 hours
- You get full diagnostic reports
Off-car (factory) CAT cleaning
For workshops and fleets that can remove the unit. Our no-hassle service includes courier collection and return, and the converter comes back ready to refit.
- Package the unit
- Our courier collects
- Factory cleaning: 1–2 days
- Returned ready to fit
We confirm the problem before we clean
Who does the work?
Our own trained engineers – never subcontracted – accredited to SafeContractor, SSIP, ISO 9001 and ISO 14001, so the work fits your compliance and site-access requirements without extra vetting.
How a CAT problem becomes an engine problem
A catalytic converter turns harmful gases into less toxic emissions. Over time, deposits build up on its honeycomb – and that’s when back pressure starts to rise.
Why deposits form:
- Short trips and stop-start work – the converter never gets hot enough to burn off carbon
- Contamination – leaking oil or coolant coats and “poisons” the honeycomb
- Rich fuel mixtures – unburnt fuel from faulty spark plugs or leaky valves
What restriction does:
- Back pressure rises and exhaust can’t escape freely
- Heat radiates through the floorpan – the unit can glow red
- Fuel economy drops as the ECU compensates
- The vehicle may enter limp mode to protect itself
- Left long enough, the substrate melts – then it’s a replacement
Converter stolen rather than blocked? That’s a different problem – see our guide to catalytic converter theft in the UK.
CAT cleaning for every kind of fleet
Petrol and diesel – from a single van to a full depot. Clean CATs and DPFs in the same visit.
CAT cleaning FAQs
Can a blocked catalytic converter be cleaned instead of replaced?
Will cleaning clear a P0420 code?
How long does it take?
On-car or off-car – which do we need?
Do you clean petrol and diesel converters?
Can you clean CATs and DPFs in the same visit?
How much does it cost?
Speak to our commercial team
0333 366 2018Or contact Shaun Clarke directly: 07495 405160 · shaun@dpf-fixer.co.uk