Will a 3 cylinder 1997 Geo Metro engine work in 1994 Metro?

The 3-cylinder engine from a 1997 Geo Metro will not work in a 1994 Geo Metro. The 3-cylinder engine was introduced in the 1995 Geo Metro, and it is not compatible with the earlier model years. The main difference between the two engines is the block and head design. The 3-cylinder engine has a different bore and stroke, as well as a different head design, which means it will not bolt up to the 1994 Metro's transmission or engine mounts. Additionally, the 3-cylinder engine uses a different fuel injection system and electronic control unit (ECU), which are not compatible with the 1994 Metro's wiring harness.