What P0171 means
System too Lean (Bank 1)
Common causes (general)
Before spending money on parts, verify the code with a scan tool and read freeze frame data. Freeze frame captures every sensor value at the moment the code set — this is often enough to figure out the root cause without further testing.
Manufacturer-specific descriptions
Different manufacturers use this code for slightly different failure modes. Here's what your specific make means by P0171:
| AUDI | Control module software needs to be updated, Vacuum leaks (intake manifold gaskets, vacuum hoses, PCV hoses, etc.), Mass air flow sensor, Plugged fuel filter or weak fuel pump, Plugged or dirty fuel injectors |
| BMW | System Too Lean |
| BUICK | System Lean Bank 1 |
| FORD | System Too Lean (Bank 1) |
| HONDA | Fuel System Too Lean |
| MITSUBISHI | System Too Lean (Bank 1); Fuel trim СЏtoo lean |
| NISSAN | System Too Lean (Bank 1) |
| VOLKSWAGEN | Fuel Trim System Lean Bank 1 |
Read this code on your own car
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