2008 Impala LS 3.5L Engine P0172 Code - Oxygen Sensor and Fuel Trim Issues
I own a 2008 Impala LS equipped with a 3.5-liter V6 engine. I've recently replaced the thermostat, air filter, spark plugs, and cleaned the MAP sensor. Despite these efforts, the vehicle continues to display a P0172 diagnostic trouble code, indicating a rich fuel mixture in the intake system. A recent emissions test failed, with the system reporting that the oxygen sensor heater, oxygen sensor, evaporative emission control system, and catalytic converter are not yet ready. I'm seeking advice on how to resolve this issue or what additional diagnostics might be necessary to address the P0172 code effectively.
Is this vehicle running on regular gasoline or is it a flex-fuel setup? This could impact fuel mixture readings and affect how the P0172 code behaves.