Save P0174, associated codes and available data. Tell the workshop the exact model, engine and symptoms. Check vehicle-specific possibilities before replacing parts; clear codes only after repair.
What bank 2 means, and how P0171 differs
P0174 refers to the lean condition on bank 2; P0171 refers to bank 1. Bank location follows engine architecture, not a universal left/right direction from the driver's seat. Use documentation for your exact vehicle before locating any part.
Both codes together may point the workshop toward something affecting both banks. P0174 alone can narrow the search, but it does not prove which component failed. Keep misfire, airflow and catalyst codes too, together with any available freeze-frame data.
- P0174 alone or together with P0171?
- Steady or flashing light, misfires or lost power?
- Cold, warm, idle or under load?
- Recent intake or exhaust work?
Three manufacturer cases, three different decisions
GM bulletin 22-NA-171 covers certain North American Colorado and Canyon 3.6 LGZ vehicles. A rubber intake boot may crack. The bulletin directs inspection and explicitly sends technicians to further diagnostics if the boot is sound.
GM PIP5681 concerns 2018–2019 Enclave and Traverse 3.6 LFY vehicles where exhaust noise and various codes, possibly including P0174, may accompany a damaged bank 2 exhaust pipe or weld. Porsche bulletin 2100.2 describes an improved diagnostic strategy and a workshop software update for specific 2020–2021 Macan GTS cars. None is a universal repair for P0174.
| Vehicle, engine, years | Context | Manufacturer finding and limit |
|---|---|---|
| Chevrolet Colorado / GMC Canyon, 3.6 LGZ, 2017–2022 | P0171 and/or P0174 | GM 22-NA-171: inspect intake boot; continue diagnosis if sound. |
| Buick Enclave / Chevrolet Traverse, 3.6 LFY, 2018–2019 | Exhaust noise; P0174 among possible codes | GM PIP5681: inspect the bank 2 pipe and weld. |
| Porsche Macan GTS type 95BBL1, 2020–2021 | Lean-mixture error in specified conditions | Porsche 2100.2: workshop check and possible software update, no automatic part replacement. |
Evidence: official manufacturer documents checked 9 October 2026. North American market, engine, model year, type and symptoms limit each case. They do not measure failure rates or establish European OBDPhone® compatibility.
What to do before buying a part
With a flashing warning light, strong misfires or marked power loss, ease off, stop safely and seek professional advice. With a steady light and normal driving, arrange diagnosis before symptoms worsen. A code alone cannot certify the next journey as safe.
Give the workshop the exact codes, when they appeared and recent service history. Ask which explanation best fits the evidence: intake, fuel supply, measurement, exhaust or control strategy. A matching VIN and market matter before using a bulletin. An oxygen sensor may be correctly reporting a real lean condition; P0174 alone does not condemn it.
How OBDPhone® helps
OBDPhone® reads generic engine and emissions fault codes and available engine data. It helps preserve P0174, any P0171 and relevant context for the workshop. Data availability varies by vehicle; a missing reading does not prove a healthy system.
Clear codes only after repair. ABS, airbags, traction batteries, coding, programming and manufacturer-specific functions are not guaranteed. Check compatibility or contact support@obdphone.com. Official sources last checked 9 October 2026.
Frequently asked questions
The essential answers.
Does P0174 mean I need an oxygen sensor?+
No. The sensor may correctly report an actual lean condition; the cause needs diagnosis.
How is P0174 different from P0171?+
P0174 concerns bank 2 and P0171 bank 1. Whether one or both appear helps plan checks, not prove the fault.
Can an air leak set P0174?+
Yes on some vehicles. GM 22-NA-171 documents one specific example, not a rule for every engine.
Should I clear P0174 before a garage visit?+
Keep codes and available data first. Clear only after repair.
This guide supports an initial understanding. It does not replace the vehicle manual, manufacturer safety instructions or an assessment by a qualified professional.
Primary sources
Reviewed to verify the facts and show why procedures depend on the vehicle.