The diagnostic codeP0172 OBDII means that an O2 oxygen sensor in bank 1 found that there is not enough oxygen in the exhaust. Remember that in 6, 8- and 10-cylinder engines, bank 1 belongs to the part of the engine that has cylinder #1.
This DTC Code is very similar to code P0175, and your car may indicate both codes at the same time.
Symptoms of fault code P0172 Generic
It is likely that there is no problem when driving the vehicle.
During engine start there are faults.
Causes of OBD2 P0172 Generic
It is likely that the MAF sensor is defective or dirty.