Hi peter, i dont know these Daewoo's very much but at 2000 rpm i would of like to see a higher vacuum than 470 mbar & if this car runs a MAP sensor as the load sensor this would cause the engine to go rich which is what the scope reading is showing at 3000 rpm,so maybe slightly block exhaust, cam timing, vacuum pipe to map sensor if fitted, blocked air filter, EGR valve stuck slightly open or the MAP sensor its self
hope this helps Darren