What does P0171 system to lean bank 1 mean on my 2000 Lexus RX300?

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)

https://repairpal.com > obd-ii-code-p0174
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)

https://www.yourmechanic.com > Articles
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 ...

https://www.samarins.com > diagnose > p0171
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 ...

You would better served if you changed all of them, they are the same age.

Here is a forum from Lexus owners discussing the same problems that you are https://us.lexusownersclub.com/forums/topic/64288-code-p0171-b1-too-lean

here what it means
https://www.obd-codes.com/p0171 P0171 System Too Lean Bank 1 P0171 OBD II Trouble Code Fuel System Too Lean Bank 1

the p0300--p0301-p0302=p0303 are misfire codes and can mean needs tune up or wiring problem and p0171 is system to lean bank 1 with this code if you correct it will probably correct the misfire codes your receiving
http://www.obd-codes.com/p0171 Fixing Hesitating Car P0171 Code YouTube P0171 System Too Lean Bank 1

It could be caused by many things, but generally it means that your engine is running too lean - usually indicating a vacuum leak. It could also be that the O2 sensor is bad and giving a false reading.

Hi there:
P0171 - System Too Lean (Bank 1)
P0174 - System Too Lean (Bank 2)
Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.

You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.

A code P0171 or P0174 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor.

Possible solutions include:
In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper fuel pressure

Hope this helps.

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=System Too Lean Bank 1,
not cylinder 1,it means the oxygen sensor on the drivers side exhaust was stuck on lean and set a code.
doesn't mean you need to change the oxygen sensor yet,first clear the code and see if it corrected its self.

what are the new codes clearing / resetting doesnt fix the problem the p0171 code has about ten different causes just changing or cleaning the sensor may not have been your problem
P0171 System Too Lean Bank 1 rescan and get all codes then look up each one most sites have causes and solutions for obd ll trouble codes