My 2001 cadillac deville keeps giving me dtc code system to lean

Question edited for clarity. It is P-Zero 0, not P-oh O.
Please always include 'year make model' first 3 words, or it it is difficult to answer and some vehicles are slightly different or more precise and will show known issues.

P0174 - OBD-II Trouble Code Fuel System Too Lean (Bank 2)

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When a vehicle has the fault code P0174, it means that computer can no longer automatically adjust the mixture between air and fuel. Code P0174 applies to V ...

P0174 OBD-II Trouble Code: System Too Lean (Bank 2)

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Code P0174 indicates that there is a lean condition detected by the Engine Control Module (ECM). A lean condition will be created if there is too much air, and ...

P0151 Code - What Does It Mean & How To Fix It - OBD2PROS

https://obd2pros.com > dtc-codes > p0151
A P0151 code is caused by an ECM (Engine Control Module) receiving a signal indicating the O2 sensor for bank 2 sensor 1 has failed to increase the voltage ...

Code P0171 - System Too Lean: Symptoms, causes, common ...

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Jul 10, 2021 - The OBDII trouble code P0171 - System Too Lean (Bank 1) means that the engine air-fuel mixture is too lean, or there is too much air and too ...

• DTC P0171 Fuel Trim System Lean Bank 1
• DTC P0174 Fuel Trim System Lean Bank 2
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The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without oxygen sensor (O2S) input. During Closed Loop, the O2S inputs are added and used by the ECM to calculate short and long term fuel trim (FT) fuel delivery adjustments. If the O2S indicates a lean condition, FT values will be above 0 percent. If the O2S indicate a rich condition, FT values will be below 0 percent. Short term FT values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term FT makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the ECM detects an excessively lean condition, DTC P0171 or P0174 sets.
Diagnostic Aids
• Excessive resistance in the fuel injector ignition 1 voltage circuit or the fuel injector control circuit may cause the following symptoms:
- Lean condition
- Misfire
- Rough idle
• The system will go lean if an injector is not suppling enough fuel.
• A lean condition could be present during high fuel demand.
• A malfunctioning MAF sensor can cause this DTC to set. Refer to DTC P0101 .
• Review the Failure Records with a scan. If an intermittent condition is suspected, refer to Intermittent Conditions .

DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0420 Catalyst System Low Efficiency Bank 1
• DTC P0430 Catalyst System Low Efficiency Bank 2

This code could mean the catalytic converter on that bank has failed .

Causes of lean condition trouble codes P0171 P0174 GM 5 3L

P0420 P0430 catalytic converter catalyst inefficiency code diagnosis

DTC code PO400 could be caused by a clogged EGR valve or EGR tube. try cleaning the EGR valve, tube
DTC code PO171 is fuel system too lean bank 1
DTC code PO174 is fuel system too lean Bank 2
Most likely suspects are O2 sensors, But can be caused by vacuum leaks and also can be Mass airflow sensor (MAF) try cleaning with electrical parts cleaner
DTC code PO 302 is a misfire at cylinder # 2
Check spark plugs and wires
Try cleaning the EGR Valve first along with changing the spark plug first, and see if any codes erase, in other words start with the cheaper fixes first, as some problems can be causing the other other codes

code P0171 is ; system too lean (bank1)
code P0174 is . system too lean (bank 2)

Determining exactly what of the thousands of parts on a modern car is broken is as difficult as doing the repairs many times. IN this video you'll learn how to diagnose and fix error codes P0171 and P0174 on a 2001 Ford Escape, which indicate vacuum problems.http://www.lightdeal.co.uk/

The code P0171 and P0174 have the same mean that "System Too Lean"
OBD2 code scanner

hi, this is an obd2 trouble code table, can help you understand the code. and this tool connects this tool can solve your problem,hope help.

P0313 - Misfire Detected with Low Fuel
P0174 -System too Lean (Bank 2).
P0171 -System too Lean (Bank 1).

P0171 and P0174 mean "system too lean" for banks 1

P0171 indicates a lean condition. The most common cause of this is a defective mass air flow sensor. Also check if any vacuum leaks. P0174 OBD-II Trouble Code

Technical Description

System Too Lean (Bank 2)

What does that mean?

Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust.

Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

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Thanks.

Hi
171 system too lean
174 system too lean
2195 - 02 ozygen sensor signal stuck lean Bank1 Sensor 1
2197- 02 ozygen sensor signal stuck lean Bank 2
Sensor 1
The 2 front 02 sensors are located on the front of
the exhaust manifold.
Should solve problem and increase gas mileage.