Duplex stainless-steel exhaust system with 1 × 100 mm outlets on the left and right for Volvo C70 II Convertible T5, type M — TA Technix

A complete exhaust system replaces everything downstream of the catalytic converter. Its main effect is sound: less restrictive mufflers, a more pronounced low tone, and a sharper-sounding rise in revs. In terms of power, the gain exists but remains modest on a stock engine, because the restriction in a standard engine is mainly upstream - the catalytic converter and downpipe.

The second effect, less often highlighted but more lasting: weight and durability. A stainless steel exhaust does not rust, can still be removed in ten years, and weighs less than an original aluminized-steel exhaust. On a car you intend to keep, it is the part you only install once.