Exhaust System Maintenance and Common Problems

Your vehicle's exhaust system does more than silence the engine. It directs harmful gases away from the cabin, controls back pressure to optimise engine performance, reduces emissions through the catalytic converter, and filters diesel particulates through the DPF. Problems with any part of the system affect all these functions.

The Components of an Exhaust System

• Exhaust manifold — collects gases directly from the engine head
• Catalytic converter — converts harmful CO, HC, and NOx gases into less harmful CO2, N2, and water
• DPF (diesel only) — filters particulate matter from diesel exhaust gases
• Middle section / centre pipe — carries gases from the catalytic converter to the back box
• Back box / silencer — reduces exhaust noise to legal levels
• Mounting hangers and brackets — support the system under the vehicle

Common Exhaust Problems

• Rust and corrosion — particularly on the back box and joints, caused by condensation and road salt
• Blowing joints — gaskets and flanges deteriorate, allowing exhaust gas to escape noisily
• Broken mounting rubber — allows the exhaust to rattle and can cause stress fractures
• Catalytic converter failure — often preceded by a rattle (broken internal substrate)
• DPF blockage — particularly on vehicles used for short journeys

Can I Drive with a Blowing Exhaust?

A blowing exhaust is a MOT failure and should be repaired promptly. More importantly, a blow near the front of the exhaust can allow exhaust gases (including carbon monoxide) to enter the engine bay and potentially the cabin. Don't delay exhaust repairs.

PKA Automotive carries out exhaust inspections, repairs, and replacements for all vehicles. Many exhaust faults can be repaired rather than replaced, saving you money.