EPA initiated the comment period on the notification of intent to certify equipment filed by Engine Control Systems (ECS) of Newmarket, Ontario. ECS has applied for certification of equipment applicable to all Cummins L-10 engines and all other 4-stroke engines that were originally manufactured prior to and including 1993. The equipment being certified is a converter muffler (CM) containing an oxidation catalyst.

The notification of intent to certify states that the candidate equipment will reduce PM emissions by 18% or more, on any 1985 to 1993 4-stroke diesel engines which either: (a) Have not been rebuilt and are not in need of a rebuild; or (b) have been rebuilt to its original configuration; or, (c) have been rebuilt with the rebuild kit manufactured by the Cummins Engine Company and certified under the urban bus retrofit program (60 FR 64046, 13 December 1995).

This equipment cannot be used in compliance with the UBRR Program 1 because the emission data does not demonstrate at least a 25% reduction in PM. If certified, the use of this equipment by urban bus operators will be allowed for operators who have chosen to comply using Program 2 only, i.e. the fleet averaging of PM reductions.

The CM is stated to be maintenance free. The engine fuel to be used with this equipment is standard diesel fuel with a maximum sulfur content of 0.05 wt.% sulfur.

A 19% PM reduction was demonstrated by ECS in testing performed on a 1987 Cummins LTA10B 240 horsepower urban bus engine. Fuel consumption with the candidate equipment installed was 0.403 lb/BHP-hr compared to 0.397 lb/bhp-hr for the baseline test. The exhaust restriction during the baseline test was 2.36 inches of Hg compared to 2.47 inches of Hg for the test after retrofit with the CM.

For further information contact: Anthony Erb, Engine Programs & Compliance Division (6403J), US Environmental Protection Agency, tel.: (202) 233-9259.