Exhaust & Emissions
Exhaust & Emissions
Blowing exhaust, failed emissions on MOT, or a DPF warning light — we diagnose and repair with quality parts and clear pricing.
DPF regeneration
Forced regen before replacing filter
Emissions pass guarantee
MOT retest included free
Cat & lambda sensors
OEM sensors, not unbranded
Custom exhaust welding
Sections repaired, not always replaced
What we repair
Full exhaust & emissions service
- Exhaust pipe, centre section & back box replacement
- Manifold gasket replacement
- Catalytic converter replacement
- DPF (diesel particulate filter) cleaning & replacement
- Lambda / O2 sensor replacement
- EGR valve cleaning & replacement
- Emissions diagnostic scan & readiness check
- MOT emissions retest after repair
Warning signs
Signs your exhaust needs attention
Loud blowing noise
A sudden roar or hissing from under the car — usually a blown joint, cracked pipe or failed back box.
Failed MOT emissions
High CO, HC, or NOx readings often point to a faulty cat, lambda sensor, or DPF issue.
DPF warning light
Diesel vehicles: a solid or flashing DPF light means the filter is blocked and needs attention quickly.
Rattling underneath
A heat shield loose on the exhaust or a loose mounting bracket — annoying but easy to fix.
Common questions
Frequently asked questions
Why is my car failing its MOT on emissions?
High emissions typically point to a faulty catalytic converter, a failed lambda or O2 sensor, a blocked DPF, or a rich-running engine. We diagnose the root cause before quoting for any parts.
What is a DPF and why does it get blocked?
A diesel particulate filter (DPF) captures soot from the exhaust. Short, low-speed journeys prevent it from reaching the temperature needed to self-clean (regenerate), causing it to block over time.
Can a DPF be cleaned instead of replaced?
In many cases yes — a forced regeneration or a professional clean can restore a partially blocked DPF. We'll assess your vehicle and recommend the most cost-effective solution.
Is a blowing exhaust an MOT failure?
Yes. An exhaust leaking through a crack, hole, or failed joint creates excessive noise and is an MOT failure. It's also a safety concern as carbon monoxide can enter the cabin.
Get it fixed
Exhaust or emissions issue?
235 Yeading Ln, Hayes, UB4 9AD. Quote before we start — no surprises.