P0171 Hyundai -

Question

How do i make sure that it is the sensor and not a leak.  Where can I buy the part and how much does it cost. Also is it the sensor by the fuel pump or up high by the engine. And how do i change it.

Answer 1

P0171 Fuel trim lean Bank 1

Lean condition, for this type of code a visual inspection is needed, when there is a  lean fuel trim this means you are receiving more air to fuel ratio, vacuum leak are the most common cause, MAF (Mass airflow) are anther cause, but a visual is mostly needed before anything is replaced

 Vacuum leak such as this broken vacuum hose should be inspected when there is a lean fuel trim condition