The european style exhaust system, which is the same as the Lotus prototype, does not have the catalyst or lambda fitted. To my knowledge it may be illegal to run a car in USA without these fitted? maybe the rules differ state by state. in UK the annual test checks for CO2 levels and other by-products of combustion, but on older classic cars the readings can be pretty lenient. Any good exhaust workshop could fabricate a proper system. I can give the specification to the Moderator for distribution to USA owners if it would be legal and acceptable. Please advise. regards Simon Lees-Milne, President DOC UK