P2177 on 2008-2011 Buick Enclave — System Too Lean Off Idle (Bank 1)
1 vehicles · 1 makes
Most Reported On
P2177 is an OBD-II diagnostic trouble code meaning “System Too Lean Off Idle (Bank 1).” The PCM detected that bank 1 is running lean (too much air relative to fuel) during off-idle/cruise conditions, with long-term fuel trims maxed out trying to add fuel. A lean condition under load that fuel trim cannot fully correct. This code is most commonly reported on 2008-2011 Buick Enclave.
Common Causes
Diagnostic Tools
To diagnose P2177, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
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BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
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LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
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Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
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- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P2177 mean?
P2177 stands for "System Too Lean Off Idle (Bank 1)." The PCM detected that bank 1 is running lean (too much air relative to fuel) during off-idle/cruise conditions, with long-term fuel trims maxed out trying to add fuel. A lean condition under load that fuel trim cannot fully correct.
What are the most common causes of P2177?
The most common causes of P2177 are: Vacuum or intake air leak, Weak fuel pump / restricted fuel filter, Dirty or failing MAF sensor, Clogged/leaking fuel injectors, Exhaust leak ahead of upstream O2 sensor. The specific cause varies by vehicle.
How much does it cost to fix P2177?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P2177?
Au7o has documented P2177 across 1 vehicle models from 1 manufacturers: Buick.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.