Exhaust Repairs in Northampton.

Signs of an exhaust fault

• A droning or rasping noise that grows with revs
• A rattle under the car, often from a broken mount or heat shield
• Visible smoke or soot from a joint rather than the tailpipe
• A fume smell inside the cabin, get this checked immediately
• Failed or borderline emissions at the MOT
• Loss of power with a diesel particulate filter warning

Section repairs versus full systems

Exhausts corrode from the inside, and usually one section goes first, usually a rotted rear silencer or a cracked flexi joint at the front. Where the rest of the system is sound, replacing the failed section is a fraction of the cost of a full replacement. EE Motors will tell you which applies once it is on the ramp.

Catalytic converters and emissions

A catalytic converter rarely fails on its own. It is usually killed by something upstream: a misfire, a failing oxygen sensor, or oil and coolant getting into the exhaust. Fitting a new cat without fixing the cause destroys the new one too, so the underlying fault is diagnosed first. The diagnostic scan is free.

Diesel particulate filters

DPFs trap soot and burn it off during regeneration, which needs sustained higher-speed running to reach temperature. Short urban journeys prevent that and the filter gradually blocks. Depending on how far gone it is, the answer is a forced regeneration, a clean, or replacement. Removing a DPF is not legal on a road vehicle and is an automatic MOT failure.

Frequently asked