CHE is indicated when there is no communication between the ECU and the LCD panel for three (3) seconds. Likeliest causes for this are 1) Engine Stop Switch is in the stop position, 2) Fuse is blown, 3) Connection is not good between the ECU and Speedometer. The first two are obvious, for #3, unplug and re plug the speedo unit. Also, un couple the ECU and inspect for corrosion on the ECU or the Wiring Harness side.
As for running on one cylinder, many things can cause this. Check the spark on each plug. Remove both plugs, insert in the caps, GROUND BOTH PLUGS, and hit the start button while watching the plugs. Also look for leaks in the spark plug caps. Sometimes these are easily seen sometimes not. An easy way to test this is to wrap the plug caps in electrical tape. If this solves your problem, replace the plug caps.
your problem can be caused by other things also such as low compression due to carbon build up on the valves or mis timed engine, not enough gas due to fuel pump failure or clogged fuel filter or clogged injector.