Engine Management light flashing intermittently and engine missing.

Start with a set of spark plugs and engine air filter. It could be a crank position sensor or the cam position sensor but they usually throw a code if they are bad.

didnt even know such a name was out their!sounds like one of o2 and more likely rear one ,saying I smell something out of parameter

Check engine light is flashing because of the misfire, it's a warning saying get it fixed before the $600 catalytic converter gets covered in gasoline and burns itself up. The only thing the rear O2 sensor does is monitor whether the cat is good or bad. It has nothing to do with engine management. Get the codes pulled and find out which cylinder is misfiring.

Gm used a lot of different names for this Daewoo -- Also called Chevrolet Kalos, Chevrolet Lova, Daewoo Gentra, Daewoo Kalos, Holden Barina, Pontiac G3, Pontiac G3 Wave, Pontiac Wave, Suzuki Swift+, ZAZ Vida. I don't know if a cat converter is used in the other parts of the world.

Misfire monitor is programmed to flash the check engine light when it sees a fault.