Effective 9 December 1996, Engine Control Systems Ltd. of Newmarket, Ontario received EPA certification under the Urban Bus Rebuild Retrofit program. The certified equipment is an oxidation catalytic muffler (OCM) which is a direct fit replacement for the original muffler. The OCM provides 25% or greater reduction in exhaust emissions of particulate matter (PM) for Detroit Diesel Corporation (DDC) two stroke cycle engines originally installed in urban buses from model year 1979 to model year 1993.

Urban bus operators in the USA who have chosen to comply with UBRR Program 1 or Program 2 can utilize the certified ECS OCM for engines for which it is certified that undergo rebuild.

Source: US EPA