Rather than building an improved diesel engine from scratch like EcoMotors or Achates Power, a Canadian company called NxtGen Emission Controls just wants to clean up the old ones.

The company makes an add-on for existing engines that converts diesel fuel to a cleaner-burning mix before it hits the combustion chamber. However, its products won’t be on sale until next year.

The $15.4 million investment was led by Altira. Japanese auto company Itochu also participated, along with previous investors Yaletown Venture Partners, GrowthWorks Capital, BC Advantage Funds and Polygon Financial Investments.