A blowing exhaust is noisy, can let fumes into the cabin and will fail an MOT. Most exhaust problems are cheaper to fix when you first notice them.
Signs of an exhaust problem
- Louder than usual, especially when starting from cold
- Rattling from underneath the car
- A smell of fumes inside the car
- Rust, holes or a section hanging lower than it should
- Engine management light on
- Fuel economy getting worse
Catalytic converters and DPFs
A modern exhaust does more than carry gas away. The catalytic converter cleans up the emissions, and diesels have a diesel particulate filter (DPF) that traps soot and burns it off on longer runs.
Lots of short trips mean a DPF rarely gets hot enough to clean itself, and a warning light follows. We can diagnose DPF problems and tell you whether a regeneration, a clean or a replacement is the right fix.
Emissions and your MOT
The MOT includes an emissions test. A car that’s smoking, or has a failing catalytic converter, will fail. If there’s a warning light on, get it looked at before the test.
Common questions
Can I have my DPF removed?
No. It’s illegal to drive a car without the DPF it was built with, and it will fail its MOT.
Is a blowing exhaust dangerous?
It can be. If fumes get into the cabin they can make you drowsy. If you can smell exhaust inside the car, get it checked straight away.