P0440 bank 2 system lean

System Too Lean P0171
Clean the MAF sensor and IAC valve with MAF cleaner
Inspect all vacuum and PCV hoses, replace/repair as required.
Inspect all hoses and connections in the air intake system.
Inspect and/or test the intake manifold gaskets for leakage.
Check for a dirty fuel filter and proper fuel pressure.

As a last resort, replace O2 sensor

System Too Lean P0174
Error code P0174 is described as System Too Lean (Bank 2). This means there is incorrect ratio of air and fuel on the car's engine system, specifically on Bank 2 of the Cylinder. “Too Lean” means there is too much oxygen in the exhaust.

As a last resort, replace O2 sensor

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2


p1131 p1151 p0171 p0174 p1131 p1151 p0171 p0174
All of these p1131 p1151 p0171 p0174 codes indicate a problem with a lean condition. This engine is known for vacuum leaks, so before you start throwing oxygen sensors at the problem, it pays to perform some diagnostics.
Start by cleaning the MAF sensor. Spray the sensor with CRC MAF sensor cleaner. Next, check the plastic vacuum lines, especially where they meet with rubber boots. If they are cracked or the rubber is swollen, replace the line. Then check the rubber elbow that holds the PCV valve. That elbow is a know failure point. In fact, the entire PCV tubing is a trouble spot on these engines. (thanks Ford).
After you've checked for vacuum leaks, check the operation of the oxygen sensors. The easiest way to do that is to disconnect the sensor from the harness. Connect one lead of your digital voltmeter to the black wire on the sensor and the other lead to battery negative. Then start the engine and add fuel (either propane, starting fluid, or carb cleaner) into the throttle body to force the mixture to rich. You should see a corresponding increase in voltage as you add fuel (from 0 volts to slightly less than 1 volt). Start and stop the fuel enrichment and watch the meter to see if the volts drop as you stop adding fuel. If you see no change, the sensor is dead. Replace it.
You can also use the fuel enrichment procedure to locate intake gasket leaks.
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1
P1151P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2
P0174 system lean bank 2
P0171 system lean bank 1


This is the only info that didn't come back directly to FORD (yet still mentions it) instead of GM. Not to sure you got the correct code.

Here are the resons for this fault code to set.
Possible causes - Intake air leaks
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection

P0174 System Too Lean - Bank No. 2.
P0440 Evaporative Emission Purge Control Solenoid Damaged.
It means that the solenoid that controls the evap system valve has failed and it's keeping it fully open so air is reaching the engine, messing the mixture. Replace the Evap solenoid and its valve.

oxygen sensor failure
P0171 System too Lean (Bank 1) - Read Our Article On Oxygen Sensor Codes For Help With This Generic Check Engine Light Code
P0174 System too Lean (Bank 2) - Read Our Article On Oxygen Sensor Codes For Help With This Generic Check Engine Light Code
hope this is a bit of a push in the right direction ...

DTC code p0174 means "System too lean (Bank 1)"

Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exahust). On V6/V8/V10 engines



, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

This is usually an oxygen sensor, replace the O2 sensor located above the catalytic converter before replacing the evaporator purge canister.

PO174= system too lean Bank 2. Good chance oxygen sensor acting up, may need replacement. If it's 4.6L, that's driver side of engine.

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.

P0171 System too Lean (Bank 1)
P0174 System too Lean (Bank 2)

If a car has a check engine light on and has P0171 and P0174 codes stored, the most likely cause is a vacuum leak. These codes are set by the car’s computer when it sees too much oxygen in the exhaust. Excessive oxygen readings in the exhaust will set lean codes. This does not mean that the oxygen sensors are defective. It is a common mistake for people to replace oxygen sensors when lean codes are present. Just because the code is related to oxygen sensor readings, it doesn’t mean that the oxygen sensors are bad. If both of these codes are stored this means that both banks of the engine have excessive oxygen in the exhaust. If the oxygen sensors are replaced it’s most likely that the same codes will reappear. It is very uncommon for two oxygen sensors to fail at the same time.

Therefore the most likely cause of P0171 and P0174 codes is a vacuum leak. The source of a vacuum leak can be one of many things. The most common cause of a vacuum leak is a leaky hose. Vacuum hoses over time can become dry and brittle. The rubber deteriorates and can leak causing a vacuum loss. Many times a leaky vacuum hose can be found by listening for a hissing sound. A large vacuum leak can even make the car run rough at idle. In some cases it will not idle without feathering the gas pedal.