P2180 indicates the powertrain control module has detected a persistently rich air-fuel mixture on bank 2 during off-idle operating conditions. The code sets when long-term and short-term fuel trims reach their maximum correction limits toward lean but the mixture remains rich. Bank 2 refers to the cylinder bank opposite bank 1 (which contains cylinder 1).
A degraded or contaminated sensor may report a falsely lean condition, causing the PCM to add excess fuel.
Unmetered air entering after the mass airflow sensor creates a lean reading that triggers excessive fuel enrichment.
One or more injectors dripping fuel or failing to close properly deliver extra fuel that cannot be compensated by trims.
A faulty fuel pressure regulator or restricted return line raises rail pressure, increasing injector flow beyond commanded amounts.
An MAF sensor under-reporting airflow causes the PCM to inject more fuel than the actual air mass requires.
Internal driver or processing error is possible but rare; only consider after all sensor, injector, and mechanical causes are excluded.
Contaminated fuel can cause temporary rich operation, but the code typically requires a persistent fault. Draining the tank is rarely the fix.
No. PCM failure is a very uncommon cause; drivers are sometimes told to replace it, but sensor, injector, or vacuum issues are almost always responsible.
The code may become pending or history if the fault disappears, but the MIL will remain on until the PCM completes sufficient drive cycles without the fault recurring.
Yes. A sustained rich mixture sends unburned fuel to the catalyst, causing overheating and potential substrate melting or premature failure.