The DTC P2177 OBDII code is related to the value to help control the amount of fuel injected into the engine. This code indicates that the PCM has detected a lean condition. This means that the air/fuel ratio has an excess of air. This code refers to bank number 1, i.e. the side of the engine where cylinder 1 is located.
To solve this code, you must take into account the vehicle manufacturer since the diagnostic steps depend greatly on the type of fuel system, the kind of Mass Air Flow (MAF), and Oxygen (O2) sensors.
Erratic Oxygen Sensor reading due to damage to the Oxygen
The Air Mass Flow Sensor may be faulty.
The air intake may be leaking.
Low fuel pressure.
Perhaps, there may be a faulty fuel injector.
Possible solutions of the DTC code P2177 Generic
Steps to troubleshoot the problems associated with the P2177 OBDII diagnostic code:
Review the Technical Service Bulletins (TSB).
If there are other error codes, you will have to resolve those codes first.
Once you have located the O2 Sensor and MAF Sensor, check their wires and connectors. Repair or replace any of these that show burn spots, wear, or corrosion. After you make these repairs, clear the code.
Check the signal going from the Air Mass Flow Sensor to the Powertrain Control Module by using a digital volt-ohm meter. Compare the manufacturer's specifiers with the readings obtained. Replace the MAF Sensor if it does not meet the appropriate specifications.
Replace the Oxygen Sensor.
Check for intake or exhaust leaks. Repair as required.
Test the fuel injectors to check they are in good condition. You should replace the injector that does not meet the operating conditions.