If you notice any of the following you should have your exhaust checked by a national expert to find out whether any components need replacing:

Noises

• Rattling - a rattling noise may indicate loose brackets holding the system in place
• Roaring – a roaring noise could be a potential problem with the silencer
• Hissing or popping – this could be a sign that the muffler or one of the pipes is leaking

Emissions

• Blue smoke – this could indicate a fault in the engine which is putting burnt oil into the exhaust system and resulting in blue smoke.
• White smoke - white smoke when first started is normal. If it continues, this could be due to an internal coolant leak and the white smoke is the result of burning antifreeze. If there are no water leaks underneath your car it could be a leaking head gasket or a crack in the engine.

Visual appearance

• Rust or corrosion on the pipe as well as cracks, especially where the pipes connect could.