Emissions to high for annual test

the most expensive part of 3 possible replaced 2 times.
wow.
the sensor or the wires (end to end) are bad. (just one gauge fails?)
the service manual covers how this work.

I guess you meant the IP cluster engine temperature meter reads wrong and the engine thermostat is not bad, 23 years old and thermostats have design life of 7 years../
a scan tool set to scan PID, ECT sensor tells what coolant is doing.
189f to 213F is spec, temp range

the gauge coolant temp has:

Water Temperature Indicator Sender Unit
When the engine temperature is low, the resistance of the water temperature indicator sender unit (10884) is high, thus restricting the flow of current through the gauge and moving the pointer only a short distance. As the temperature of the coolant increases, the resistance decreases, allowing more current to flow through the gauge and resulting in a corresponding movement of the pointer.

these year trucks the gauge sender is not the ECU ECT sensor
and may be single wire sender.. try mostly fail this old, not the gauge
the wire on the sender can rust or even fall off.

Check coolant temp sensor (not the sender for the dash indicator but the one that talks to the ECU). These fail often and will tell the ECU wrong temperature data such that the fuel mix can be way off. They usually do not cause check engine light to be on. This can be tested with ohm meter if you have a temp chart with readings. Easy fix.

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.

Intake air flow meter and air intake temp sensor give ECU information; then coolant temp sensor has big influence on fuel mix, throttle position sender tells ECU what driver wants, then O2 sensor(s) do fine trim to fuel mix.

ok lets start with the codes they say your getting. P??? which 1's and how many. there are few o2 sensors, are they next to the Exhaust next to the converter? MASS AIR FLOW -MAF use this, for now i am guessing, until i see the correct codes your are getting. this could be the 1 you may have below, please read it........

• P0103
  Mass Air Flow Sensor Circuit High Input
• Possible causes
• Faulty mass air flow sensor
  - Intake air leaks
  - Dirty mass air flow sensor
  - Dirty mass air filter
  - Mass air flow sensor harness is open or shorted
  - Mass air flow sensor circuit poor electrical connection
• Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.
• possible symptoms Engine Light ON (or Service Engine Soon Warning Light)
  - Engine stall
  - Engine running rough
  - Excessive fuel consumption
  - Excessive smoke
• the code is generated when An excessively high voltage from the sensor is sent to Engine Control Module (ECM).

2003 NISSAN Altima Sedan OBDII Codes List

check that there is coolant or fluid in the radiator as a coolant temp sender cannot read air as it is a vital part of the injection system for the ecu to know if the engine is cold and if sender relays no reading it is telling the ecu that it needs to ritchen the fuel mixture (possibally the reason for the fast idle) to get the engine up to normal operating temp as soon as possible.it you live in a really cold climate a thermostat that is jamed in the open position will cause it a long time to reach a warm reading. hopefully it is just the sensor wire off the coolant temp sender and by replacing it will return ever thing to normal

First, your engine has fuel injection and has no choke. In a carbureted car, the reason there is a choke is to restrict air flow in order to change the mixture of air and fuel entering the engine. Since fuel flow cannot be easily altered you just limit the amount of air going in, resulting in a rich mixture.
In an injected engine, air flow remains the same and additional fuel is added by keeping the injectors open longer.
The computer gets information from several sensors in order to know when the engine is cold or hot, or, to know what the outside air temp is. The sensors that are primarily responsible for that are the coolant temp sender and the intake manifold air temp sender. However, the coolant temp sender cannot work properly unless you have the correct thermostat installed (195 degree (f)) But, generally that helps more in making it run correctly after it's warm.
Therefore, check or replace the coolant temp sender and the intake manifold air temp sender.
Testing can be done using a digital multi meter following instructions found in either chiltons or haynes manuals,
Also make sure spark plugs, ignition wires and the cap, rotor, and coil (if you have them) are in good condition as when cold, any moisture or condensation on ignition parts can cuase spark bleed off and make the engine run poorly as well.

Intake Air Temperature Sensor Operation The Intake Air Temperature (IAT) sensor is a variable temperature sensitive resistor. Sensor resistance will change based on air temperature. The higher the temperature, the lower the resistance. The Engine Management System (EMS) provides a reference voltage and monitors the voltage drop between a fixed value internal resistance and the sensor resistance. This is called a voltage divider circuit.
IAT sensor values are used by the EMS to assist with the calculation of idle speed, fuel mixture and spark advance.
Inaccurate voltages from the IAT sensor may affect pulse-width, idle quality and tail pipe emissions. Intermittent signals may cause hesitation, stumble and surging. If an IAT sensor failure accompanies an Engine Coolant Temperature (ECT) sensor failure cooling fan operation may also be affected.
Some manufacturers' incorporate the Intake Air Temperature (IAT) sensor as part of the Mass Air Flow (MAF) sensor, or air flow meter. Refer to current service information for specific applications.
Related Symptoms The following symptoms can be caused by a faulty IAT sensor due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit.

• Extended crank time when the engine is cold
• Poor fuel economy
• Spark knock

Hello. I can assist you. Generally when a scan is done, the technician will clear out all of the codes and hope that the problem self corrects. I am glad you passed the state emissions test. Now let's get to the bottom of the hesitation. Generally all lincoln and ford cars that hesitate like yours have a problem with the "mass airflow sensor". Most likely you will need to replace it.
The Air Flow Sensor or Mass Airflow Sensor (MAF) is one of the components of an electronic fuel injection system and is found in many of modern vehicles. The Mass Air Flow sensor is usually installed inside the intake air duct between the air filter and the engine. The Mass Air Flow sensor is used to measure the amount of air entering the engine. This measurement is used by the engine computer or ECM to calculate proper amount of fuel injected into the cylinders in order to provide optimum combustion and low emissions.
Problems with Mass Air Flow sensors are common. Bad or contaminated Mass Air Flow sensor can possibly cause a wide range of various vehicle driveability problems such as stalling, especially when the engine is cold, misfiring, poor acceleration, etc.
In addition, a problem with the Mass Air Flow sensor often causes the "check engine" or "service engine soon" light in the vehicle instrument panel to illuminate.
The "check engine" or "service engine soon" light comes on when the engine computer detects some fault in one of the components of the emission control system.

Have the 02 sensors checked.