fuel consumption and P1123

good day
i was sent from many weeks for my defect (hyundai accent 2000) i was
have those code (P0422 - P1123)

p0422
resolved it by change O2 sensor and release flex pipe for a new one

found the P0422 not come back

P1123
i tested it but found when i unplugged the (pressure regulator) and
turn on the engine and close the engine and return plug to it and turn
engine on after many miles found the )check lamp off)

but after many day found this code return back and do this again

--- make test for my car in the scan tool tell me the o2 sensor is
complete and fuel system is complete but tell me the Evaporative
incomplete

what can i do in this case

and i found my fuel consumption is high usually at 100 K/m take 15
liter and decrease to be 12 liter at 100 K/m

without open the A/C

need to know the economy fuel i read in the country take 9 liter and
at the road take 7 liter every 100 K/m are this is right

 

waiting replay