Hesitates? When Trying To Accelerate

[Delta38]

Hi, so I have a corolla 1.6 e11? I think, the 5 door one, and when I try to accelerate its slow and once it reaches 2000rpm it seems like it loses power/jerks then it suddenly all comes at once,

It does have an engine management light, p0171, system too lean bank 1, which I think it comes up as a 02 sensor on the diagnostic machines, are these 2 problems related? And if not how would I go about sorting the first problem out

[Awebb180]

I would get the o2 sensor changed first and get the codes clear. when were the plugs/airfilter etc last changed?

Alex

[Delta38]

Sparks were changed a few days ago and the air filter i just gave a clean as it looked pretty clean

EDIT: The technician I took it to did a live reading of the 02 filters, and he said the pre cat one is a bit slow compared to the post cat/normal