An exhaust system comprising: an exhaust treatment component; and an exhaust pipe connected to the exhaust treatment component, the exhaust pipe comprising an exhaust system component, the exhaust system component comprising: a pipe having a pipe wall with an inner surface defining an exhaust gas passage and with an outer surface; a louver bridge portion formed in the pipe wall, the louver bridge portion having bridge ends transitioning from adjacent pipe wall portions to a bridge raised portion with raised side edges detached from adjacent opening side edges of the pipe wall, wherein each bridge side edge is radially outward of the adjacent opening side edge of the pipe wall to define a louver opening at each of two opposite sides of the louver bridge portion, wherein the bridge raised portion radially outwardly covers an open region partially defined by the opening side edges at the inner surface of the louver bridge portion and the open region defines a flow path from the exhaust gas passage to each louver opening at the two opposite sides of the louver bridge portion, characterized in that the louver opening at each of two opposite sides of the louver bridge portion forms a portion of the flow path and directs a portion of gas flowing in the pipe out of the pipe through the respective louver opening to produce a gas divergence of flow that is parallel to the exhaust gas flow within the pipe and which does not cause radial impingement of hot exhaust gas, so that fluid communication through the two louver openings, between the exhaust gas passage and an exterior environment of the component, attenuates resonant frequencies generated during operation of an exhaust system to which the exhaust system component is connected. an exhaust treatment component; and an exhaust pipe connected to the exhaust treatment component, the exhaust pipe comprising an exhaust system component, the exhaust system component comprising: a pipe having a pipe wall with an inner surface defining an exhaust gas passage and with an outer surface; a louver bridge portion formed in the pipe wall, the louver bridge portion having bridge ends transitioning from adjacent pipe wall portions to a bridge raised portion with raised side edges detached from adjacent opening side edges of the pipe wall, wherein each bridge side edge is radially outward of the adjacent opening side edge of the pipe wall to define a louver opening at each of two opposite sides of the louver bridge portion, wherein the bridge raised portion radially outwardly covers an open region partially defined by the opening side edges at the inner surface of the louver bridge portion and the open region defines a flow path from the exhaust gas passage to each louver opening at the two opposite sides of the louver bridge portion, characterized in that the louver opening at each of two opposite sides of the louver bridge portion forms a portion of the flow path and directs a portion of gas flowing in the pipe out of the pipe through the respective louver opening to produce a gas divergence of flow that is parallel to the exhaust gas flow within the pipe and which does not cause radial impingement of hot exhaust gas, so that fluid communication through the two louver openings, between the exhaust gas passage and an exterior environment of the component, attenuates resonant frequencies generated during operation of an exhaust system to which the exhaust system component is connected. a pipe having a pipe wall with an inner surface defining an exhaust gas passage and with an outer surface; a louver bridge portion formed in the pipe wall, the louver bridge portion having bridge ends transitioning from adjacent pipe wall portions to a bridge raised portion with raised side edges detached from adjacent opening side edges of the pipe wall, wherein each bridge side edge is radially outward of the adjacent opening side edge of the pipe wall to define a louver opening at each of two opposite sides of the louver bridge portion, wherein the bridge raised portion radially outwardly covers an open region partially defined by the opening side edges at the inner surface of the louver bridge portion and the open region defines a flow path from the exhaust gas passage to each louver opening at the two opposite sides of the louver bridge portion, characterized in that the louver opening at each of two opposite sides of the louver bridge portion forms a portion of the flow path and directs a portion of gas flowing in the pipe out of the pipe through the respective louver opening to produce a gas divergence of flow that is parallel to the exhaust gas flow within the pipe and which does not cause radial impingement of hot exhaust gas, so that fluid communication through the two louver openings, between the exhaust gas passage and an exterior environment of the component, attenuates resonant frequencies generated during operation of an exhaust system to which the exhaust system component is connected.