Abstract: The insert for an engine exhaust system has at least one conical section of flexible mesh of metallic or other high temperature resistant fiber. Each section includes a rigid anchor or attachment ring having an outer diameter closely conforming to the inner diameter of the exhaust pipe, with the anchor ring being welded to the mesh material or the mesh being crimped between two concentric rings. A smaller diameter support ring may be provided at the opposite end of the conical mesh, with the support ring braced by a series of radial arms. A coil spring may be placed within the mesh for additional support, and/or the outer surface of the mesh may be wrapped with a glass fiber batt for additional sound control if desired. The device may serve to reduce the sound output of the exhaust system, and/or may serve as a spark arrestor as well.