I was a vehicle mechanic in that era and the Dodge Omni did not have an engine supplied by Mitsubishi, the engine was supplied by Volkswagen a 1.7 liter engine then for the last few years it had a 1.6 liter engine made by Renault. I am thinking you might be a bit confused on this as the Dodge Aries had optional a 2.6 liter engine made supplied by Mitsubishi with a 2.2 base engine made by OMG Chrysler.
1.6 liter dodge? the more you know...