OCTAVIA 1 1U5 motor fault code

Hello everybody,

I have always this fault code: 16555, Fuel trim system too lean bank1,

after cleaning all it's possible in system, I do not find enything else..

Even is posible the fuel pump or  fuel filter??

Also in basic settings: group 046, it is imposibble to start test on, even though the brake pedal long time..

Whether is theese problems are common origin?

Thank you for your answer.