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P0171 on the 2019 Buick Cascada

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

Bulletins for this model year that name P0171
N2323953202023-02-16. Service bulletin. Some vehicles may have a condition where cracks can develop in the diaphragm of the Positive Crankcase Ventilation (PCV) pressure regulator valve. This valve is a part of the engine camshaft cover. If this were to occur, excess air could be drawn into the engine intake. As a result, the engine may run rough, especially during idle, the Malfunction Indicator Light (Check Engine Light) would illuminate and a diagnostic trouble code for Fuel Trim Lean (P0171) or other airflow related DTC would set. Dealers are to replace the engine camshaft cover as necessary. The repairs will be made at no charge to the customer.

1 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.