If a baffle is collapsing and causing an exhaust restriction, you should feel it on acceleration or higher rpms. Not deceleration. You should also hear a wheezing in the exhaust note kind of like air coming out of a air nozzle.
Did they give you a reason for doing the top end work? What were the compression readings? I really have a problem with their diagnosis.
Has anyone had their valves redone due to a stalling problem?? Not
