(a) General. Use the exhaust system installed with the engine or one thatrepresents a typical in-use configuration. This includes any applicable aftertreatment devices. We refer to exhaust piping as an exhaust stack; this is equivalent to a tailpipe for vehicle configurations.
CFR 40-1065.130-2014 history
2014CFR 40-1065.130-2014 Protection of Environment. Part1065:Engine-testing procedures. Section1065.130:Engine exhaust.