How do I adjust and balance the air flow intake and fuel ratio?

Unlikely fuel filter.

Intake air leak is a possibility; perished vacuum hose, pcv valve, brake booster...

Might be the air/fuel ratio. If nothing else is found to be faulty it would be a good idea to have the injector spray patterns checked.

Slight defects of the intake valve seats can also affect the air/fuel ratio at low speed. A cylinder leakage test would discover that.

P1800 is the VIAS system. Most likely the intake runner control vacuum actuator is defective. Where did you get the ABS info?
P1273 NISSAN - Air Fuel Ratio Sensor 1 Bank 1 Lean Shift Monitoring.
Possible causes - Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
-Intake manifold or vacuum hose leaking (check this first)
- Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
- Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
- Fuel pressure
- Faulty Fuel injector
- Faulty Air Flow Meter
If all seems ok then replace the cylinder bank number one O2 sensor and the bank two sensor, replacing only one sensor can lead to another check engine light. These are the sensors before the catalytic converter.

P0171 - System Too Lean Bank 1 Share
1 ' Add Comment 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
What does this mean? Tech notes
If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replaced the air filter and clean the air flow meter. If the problem persist the front oxygen (O2) sensor may need to be replaced.
What does this mean? When is the code detected?
- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption
P0171 Description
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the Malfunction Indicator Light (MIL) (2 trip detection logic).
Read more: http://www.autocodes.com/p0171.html#ixzz3t65yA9xI

P1273 Nissan P1273 Nissan - Air Fuel Ratio Sensor 1 Lean Shift Monitoring Bank 1 Possible causes
- Faulty Air fuel ratio (A/F) sensor 1 Bank 1
- Faulty Air fuel ratio (A/F) sensor 1 heater Bank 1
- Fuel pressure
- Faulty Fuel injector
- Intake air leaks
- Faulty Air Flow Meter
Most probable is you have a bad heater in your upper bank 1 O2 sensor. Replace all of your O2 sensors.

Read more: http://engine-codes.com/p1273_nissan.html#ixzz3lgP7CTD8
Read more: http://engine-codes.com/p1273_nissan.html#ixzz3lgOwiMU8

A mass (air) flow sensor (MAF) is used to find out the mass flowrate of air entering a fuel-injected internal combustion engine.
The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the ambient temperature, altitude and the use of forced induction, which means that mass flow sensors are more appropriate than volumetric flow sensors for determining the quantity of intake air in each cylinder. (See stoichiometry and ideal gas law.)
There are two common types of mass airflow sensors in use on automotive engines. These are the vane meter and the hot wire. Neither design employs technology that measures air mass directly. However, with additional sensors and inputs, an engine's ECU can determine the mass flowrate of intake air.
Both approaches are used almost exclusively on electronic fuel injection (EFI) engines. Both sensor designs output a 0.0-5.0 volt or a pulse-width modulation (PWM) signal that is proportional to the air mass flow rate, and both sensors have an intake air temperature (IAT) sensor incorporated into their housings for most post OBDII vehicles. Vehicles prior to 1996 could have MAF without an IAT. An example is 1994 Infiniti Q45.
When a MAF sensor is used in conjunction with an oxygen sensor, the engine's air/fuel ratio can be controlled very accurately. The MAF sensor provides the open-loop controller predicted air flow information (the measured air flow) to the ECU, and the oxygen sensor provides closed-loop feedback in order to make minor corrections to the predicted air mass.

P0171 Chrysler - Fuel System Lean

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

Tech notes
If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replaced the air filter and clean the air flow meter. If the problem persist the front oxygen (O2) sensor may need to be replaced.

When is the code detected?
- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)

Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption


P0171 Chrysler Description
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.

In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the Malfunction Indicator Light (MIL) (2 trip detection logic).




P0171 Chrysler Fuel System 1 1 Lean

Sir, your question is not very clear, but I will still try to post a solution here. Engine missing could be due to any problem in fuel system, ignition system, engine or ECM as well.

LOW ENGINE IDLE SPEED (Poor idling):
-Throttle body (do the cleaning and idle speed learning)
-A /C signal circuit
-Fuel pump control circuit
-Fuel pump
-Intake system
-P C V valve (clogged or open) and hose

ROUGH IDLING:
-Cylinder Compression
-Ignition system (Igniters, spark plugs, wiring harness)
-Spark plug fouled, gap too wide or too short. (1.00-1.1 mm)
-Fuel injector circuit
-E C M power source circuit
-Fuel pump control circuit
-Fuel pump (required pressure 44 psi - 49 psi)
-Throttle body (cleaning)
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Heated oxygen s ens or
-Mass air flow meter
-Idle hunting
-Throttle body
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Mass air flow meter

HESITATION/ POOR ACCELERATION:
-Fuel pump control circuit
-Fuel pump
-Spark plug
-Ignition system
-Fuel injector circuit
-E C M power source circuit
-Mass air flow meter
-Throttle body (do cleaning)
-Intake system
-Valve timing
-Cylinder Compression

P0174 FORD - Fuel Injection System Too lean Bank 2http://engine-codes.com/p0174_ford.htmlForum CodePossible 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 Tech notes The codes is usually set when there is an intake leak after the air flow meter, before replacing any parts check for loose or broken hoses and intake gasket leak. On Ford some models dirty air filter, and dirty or faulty air flow sensor are the cause of the problem.

It's a very common problem for the Ford Windstar. Here a link to a web site with information how to repair:
When is the code detected?- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.) Symptoms- Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel ConsumptionP0174 FORD Description The Powertrain Control Module (PCM) monitors the engine Air/Fuel mixture ratio, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The PCM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.

In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the PCM judges the condition as the fuel injection system malfunction and light up the engine light.

P0171 - Fuel Injection System Too Lean Bank 1
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection

P0174 - Fuel Injection System Too Lean Bank 2
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection

What Causes These Codes: Fuel injection system does not operate properly. The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.) The Powertrain Control Module (PCM) monitors the engine Air/Fuel mixture ratio, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The PCM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios. In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the PCM judges the condition as the fuel injection system malfunction and light up the engine light. The codes is usually set when there is an intake leak after the air flow meter, before replacing any parts check for loose or broken hoses and intake gasket leak. On Ford some models dirty air filter, and dirty or faulty air flow sensor are the cause of the problem.

Firstly, these codes are set when the fuel 'TRIMS' are out of spec (either tool LEAN - P1123, OR too RICH - P1128). The air/fuel control system, in addition to a number of sensors, includes the following components and systems: a. Intake air system. b. Exhaust system. c. Evaporative emissions control system (includes purge control solenoid valve). d. Fuel injectors. e. Fuel pressure regulator. f. Fuel pump. For the air/fuel ratio to be within limits, all of the sensors, components and systems associated with the air/fuel control system must function within normal parameters. STOP replacing parts/sensors unless you can VERIFY they are defective! The Powertrain Control Module (PCM) on Hyundai OBD II vehicles (all 1996 and later models) can adjust the engine Air to Fuel (A/F) ratio to compensate for variations in operating conditions. This adjustment only takes place during "Closed Loop" operation. The PCM uses input from the following components to determine the amount of fuel to deliver:

• Oxygen sensors
• Air flow sensor
• Coolant temperature sensor
• Intake air temperature sensor
• Throttle position sensor
• Engine speed sensor

The ability to adjust the A/F ratio enables the PCM to compensate for engine, fuel and sensor variations as well as temperature, altitude and humidity. This enables the vehicle to maintain a stoichiometric (14.7 to 1) A/F ratio that will ensure optimal engine performance and minimal emissions. Since the PCM can change the A/F ratio to compensate for a wide range of conditions, an indicator is needed to identify that a compensation has been made. Fuel Trim values shown on the HDS scan tool are the primary indicator that an adjustment in fuel delivery has taken place. The scan tool displays the PCM's A/F ratio compensation as "Short Term" Fuel Trim (ST TRIM), Long Term Fuel Trim (LT TRIM), and "Oxygen Sensor" Trim (TRIM B1 S1 and B1 S2). The most beneficial diagnostic information comes from "Short Term" Fuel Trim and "Long Term" Fuel Trim. AFTER ALL THIS, I think it's simply your Coolant Temperature Sensor giving 'FALSE' information to the engine control module/powertrain control module (ECM/PCM).