ca18de fuel economy

[ju5tify]

Hi 2 all. First of all forgive me my poor English.
What do i have:
CA18DE sticked in car by someone retarded
Mechanical transmission
ECU from CA18DE automatic
Harness from CA18DET (drop-resistor is absent)
Messed up vacuum lines. Half of them are plugged with screws. Other half is connected to wrong solenoid (the one which is on the right, for turbo). No vacuum tank. If it helps - i can draw a diagram.
I have some serious issues with fuel economy. I'ts around 17-20 liters per 100km. Oxygen sensor is working, spark plugs are replaced, throttle cleaned, injectors cleaned, but no effect. ECU diagnosis says it's all ok (code 55). What can it be? Maybe fuel pump? Or speed sensor malfunction (it never worked, and in manual it is said that it is connected to ecu)? Or maybe ECU from A/T? Or problems with the vacuum (butterfly valve perhaps).
Thanks in advance.

[compactfean]

How do you know the o2 is working? Also something to look into is the coolant temp sensor.