P0171 Hyundai tucson after driving about 60-120km

Question

Engine Light lights after about 60-120km. Faulty code p0171.
Hyundai tucson -08 2,7
When accelerating it seems to loose power
Is there any known issues

Answer 1

P0171 Fuel trim lean Bank 1

When there is a lean code condition is more to say vacuum leaks which do cause a lean condition, If there was a disconnected vacuum hose yes it will cause a lean condition, only at idle and  it will not cause loss of power when accelerating. unless the MAF air duct is torn or has a leakage allowing false air to enter. What you have is a lean condition at load, what this is not is a vacuum leak, or a 02 sensor. This is where fuel pressure has to be check. Also  check the MAF air duct for any rips torn or just not properly secured. Air filter plugged can also cause a lean condition.