Exhaust and emissions issues are an MOT failure and, more immediately, a potential ULEZ compliance problem in London. A vehicle emitting above the permitted threshold faces a daily charge in the Ultra Low Emission Zone, which covers most of inner London. A failing catalytic converter, oxygen sensor fault, or DPF blockage can push a previously compliant vehicle over the limit and trigger both an EML warning and significant daily running costs.
Mr Outcall’s vehicle diagnostics capability is central to accurate exhaust and emissions diagnosis. Fault codes related to the exhaust system, lambda sensors, and DPF are read and properly interpreted as part of both the basic scan and the full diagnostic report. This gives you a clear picture of what needs addressing, and in what order, before committing to parts or labour.
Common Exhaust & Emissions Issues in London Vehicles
- DPF (diesel particulate filter) blockage — common in city-cycle diesel vehicles
- Catalytic converter failure — EML trigger and emissions failure risk
- Oxygen / lambda sensor faults — affects fuel trim and emissions readings
- EGR valve issues — particularly on older diesel engines in stop-start use
- Exhaust blowing — joints and flexible pipes prone to cracking on high-mileage vehicles
