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I doubt i'll ever get a diff change on mine, as i do a fair amount of cruising
Yep, same. Only one exhaust port.
emmissions has a lot to do with port inlet and outlet desgin as it does placemwnt of cats
cats only efffect the nitrates of oxygen not the levels of hydrocarbons they are efeected by the combustion process including the design of intake exhaust and combustion chamber
i still fail to see a monetry value on the desgine as the cost of recertification and testing retuning of the exhaust system retooling of the assembly line distrabution and manufacture of the two exhaust systems