Please help with DT P0171- system too lean

[jojomannoh]

Hi

i have been fighting with this error(P0171) for a while now

i have an aveo LT 2006 1.6L

according to the web info.

possible faults are
-vacuum leak
-map sensor
-fuel injection system
-oxygen system

i have replaced the MAP sensor but issue is still there.

i did a carb spraying vacuum leak test but no luck also


i have attached a snapshot of my live data.

the red flags seems to be

1. long term fuel trim of 29.7%----this value is always constant. i know it should be lower but is it supposed to be constant?

2. oxygen sensor 2 is always 0.8---- is this value too high?

3. fuel trim on oxygen sensor 2 is always at 99.2 %. is this right?

4. i want to do a smoke test on the vacuum leak. where is the best place to plug in the smoke tube?
i am thinking at the opening for the MAP sensor, is this right?