P0174 The engine is running lean on bank 2
6 owner reports and 566 manufacturer filings across 196 model years from Acura, Buick, Cadillac, Chevrolet and others.
Where P0174 shows up
Source: NHTSA manufacturer communications and complaintsShowing the 25 model years where P0174 appears most; it is on file for 196 in total.
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
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P0174 by make
The same record, one make at a time: the model years, bulletins and owner reports that name P0174 on that maker’s vehicles.
What it gets filed under
What owners said
Source: NHTSA complaint databaseOwners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.
Checked code and got P0171 and P0174 which mean engine's air/fuel mixture becomes too lean for the Engine Control Module (ECM) to correct within its normal operating range there are many posts and threads about same issue on highlanders as…
The contact stated that she purchased an OBD reader and diagnosed the vehicle and retrieved codes: P0177, P0174, P0102 and P0113
When they scan the codes they usually find P0171 and P0174, but they say the codes are not active, only stored
I have an OBD reading of P0171 P0174 P219B after I changed the battery on it
566 manufacturer filings name P0174. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P0174.
- TSB000923 Service bulletin2023-02-09 · Service Brakes, Hydraulic
- TSB: Some 2014 ? 2020 model year Toyota vehicles may exhibit a hard start and/or MIL ON condition with one or more of the following Diagnostic Trouble Codes (DTCs): ?DTC P0171 and/or P0174 (System Too Lean Bank 1/Bank 2) ?DTC P0087 Fuel Rail / System Pressure ? Too Low Techstream data list analysis may reveal positive fuel trims including a no pressure condition verified by a manual fuel p
- LSB000523 Service bulletin2023-02-09 · Electrical System — Instrument Panel — Fuel Gauge
- TSB: Some 2013 ? 2020 model year Lexus vehicles may exhibit a hard start and/or MIL ON condition with one or more of the following Diagnostic Trouble Codes (DTCs): ?DTC P0171 and/or P0174 (System Too Lean Bank 1/Bank 2) ?DTC P0087 Fuel Rail / System Pressure ? Too Low Techstream data list analysis may reveal positive fuel trims including a no pressure condition verified by a manual fuel pr
- 22-NA-171 Service bulletin2023-01-19 · Electrical System — Instrument Cluster/Panel
- This service bulletin provides service information to correct a customer concern of Malfunction Indicator Lamp (MIL) Illuminated on Driver Information Center (DIC) with DTCs P0171, P0174 Set.
- BTI&05102022901 Service bulletin2022-05-10 · Fuel System, Gasoline
- American Honda Motor Co., Inc. (AHM) is searching for certain 2016-2020 MDXs, RLXs & TLXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected), P0171 & P0174 (Rear/Front Bank Fuel System Too Lean), or P219A&B (Air-Fuel Ratio Variation of Cylinder) stored. To better understand the cause of this condition, AHM would like to collect specif
- BPaS09272021 Service bulletin2021-09-27 · Fuel System, Other — Storage — Fuel Gauge System
- Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2016-2020 MDXs, RDXs & TLXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected), P0171 & P0174 (Rear/Front Bank Fuel System Too Lean), or P219A&B (Air-Fuel Ratio Variation of Cylinder) stored. To better understand the cause of this condition, AHM would like
- BPaS09232021902 Service bulletin2021-09-23 · Electrical System — Instrument Panel — Fuel Gauge
- Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2016-2020 MDXs, RDXs & TLXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected), P0171 & P0174 (Rear/Front Bank Fuel System Too Lean), or P219A&B (Air-Fuel Ratio Variation of Cylinder) stored. To better understand the cause of this condition, AHM would like
What P0174 means
Source: SAE J2012 / OBD-IIThe engine is running lean on bank 2.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about P0174
Source: NHTSA files and the OBD-II standardCan I keep driving with P0174 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.