P2177 to P2194: mixture wrong at idle, off idle or under load
The fuel mixture correction is at its limit, but only in one operating range: at idle (P2187 to P2190), off idle (P2177 to P2180) or under higher load (P2191 to P2194).
SeverityModerateUsually not urgent today, but it can get worse if left.
Can you keep driving?Drive gently, check it soonWhat does P2187 mean?
Modern engine computers keep separate mixture corrections for different operating ranges, so they can tell where the error happens. That is useful: a mixture that is lean only at idle points to something that matters most when little air flows, such as a vacuum leak, while one that is lean only under load points to fuel supply or air measurement at high flow.
What causes P2187?
- A vacuum leak, the classic cause of a lean idle that improves with speed
- A dirty mass air flow sensor that reads wrongly at certain flows
- Low fuel pressure or a weak pump, the classic cause of lean under load
- A leaking injector or a high fuel pressure for the rich codes
- A faulty upstream oxygen sensor skewing one range
What to check first for P2187
- Note which range the code names and whether it is lean or rich
- For a lean idle, smoke-test the intake for vacuum leaks
- For a lean load, have the fuel pressure measured during a road test
- Clean or test the air flow sensor and compare its reading with the expected value
Can you drive with P2187?
Usually safe to drive to a workshop. Expect rough idling or hesitation in the range named, and do not ignore it for long, because a lean mixture over time can damage the catalytic converter.
In states with an OBD-II emissions inspection, a car with the check engine light on fails the test until the fault is fixed.
Codes on this page
12
- P2177System Too Lean Off IdleBank 1
- P2178System Too Rich Off IdleBank 1
- P2179System Too Lean Off Idle
- P2180System Too Rich Off IdleBank 2
- P2187System Too Lean at IdleBank 1
- P2188System Too Rich at IdleBank 1
- P2189System Too Lean at IdleBank 2
- P2190System Too Rich at IdleBank 2
- P2191System Too Lean at Higher LoadBank 1
- P2192System Too Rich at Higher LoadBank 1
- P2193System Too Lean at Higher LoadBank 2
- P2194System Too Rich at Higher LoadBank 2
Related codes
Checked on · Rafael Soares
These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.
