An exhaust flow tube system for use with emissions test equipment and associated parts and systems

An exhaust flow tube system for use with emissions test equipment, the system comprising: a primary flow tube configured to receive exhaust gases from an engine exhaust pipe and to deliver the exhaust gases to emissions test equipment; a secondary flow tube configured to receive exhaust gases from the engine exhaust pipe and to deliver the exhaust gases to the emissions test equipment; a valve configured to control the flow of exhaust gases through the secondary flow tube; and a control system configured to receive a signal indicative of the flow rate or likely flow rate of exhaust gases from the engine exhaust, and to control the operation of the valve to alter the flow of exhaust gases through the secondary flow tube dependent on the signal.