up stream sensor still getting error code after replacing it Could it be the mass airflow sensor.

Question

replaced the up stream sensor still getting error Could it be the mass airflow sensor

Answer 1

P0171 Fuel trim lean Bank 1

Yes it can be the MAF sensor, what the 02 sensor does is just reported the condition. , Vacuum leak are also common cause for a lean code condition, check the MAF air flow duct from the MAF to the throttle body look for any cracks tear or opening that will allow false air to enter after  the MAF sensor