After diagnosis, the following results came up.

Car Make: NISSAN ALTIMA 2003 2,5 I4

P0460 - Fuel Level Sensor
P0031 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
P0037 - HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
P0128 - Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

Kindly help interpret (and offer the needed solution, please )
Thanks a million !!

There's a fuse for both oxygen sensors. It's is unlikely both will go bad at the same time except you have a major exhaust leak to skew the o2 readings. So, check your fuses and change your thermostat.
Your fuel economy must suck majorly.

By the way, if all your fuses check out then it's a wiring issue with the upper sensor.

nissparts: There's a fuse for both oxygen sensors. It's is unlikely both will go bad at the same time except you have a major exhaust leak to skew the o2 readings. So, check your fuses and change your thermostat.
Your fuel economy must suck majorly.

How much does a thermostat go for, sir?

as for fuel level sensor,it might be an indication that your fuel pump module may be on its way out

on oxygen sensors,I think you should check whether your catalytic converter is still present in the silencer port.then a data stream of the O2 sensors wouldn't be a bad idea a well

perhaps the thermostat has been removed!do you have your fan running directly i.e fan start to work as soon as you turn the ignition-KOEO(key on,engine off)?or if its viscous fan have you welded the fan? you might need to revert to factory arrangement if you have altered the operation of the cooling system.

@femicousim

thanks for you reply. what do you mean by DATA STREAM of the 02 sensors? I don't get it at all . .
No the thermostat is still in there . . And the fans DO NOT run when ignition is turned on . . .

And i noticed the temp. gauge is always below the half-way mark, and never rises whether A/C is on full blast,
in traffic for 3hrs, or while speeding at 160 kph on the expressway . . .

data stream refers to the checking of values of components in the vehicle via a scan tool, this way you are able to establish whether a particular sensor/actuator is working well or not.

on the thermostat function DTC it might be the engine coolant temp sensor or the thermostat valve itself is stuck open

Good day ,pls I scanned and got the following codes..p1135 A\F sensor..heater circuit.bank 1 sensor 1.... P1155 A F sensor heater circuit bank 2 sensor 1...toyota camry 04..Big dady

chinero121: Good day ,pls I scanned and got the following codes..p1135 A\F sensor..heater circuit.bank 1 sensor 1.... P1155 A F sensor heater circuit bank 2 sensor 1...toyota camry 04..Big dady

@ chinero
i guess you are referring to P0135 & P0155, it has to do with your A/F sensor(oxygen sensor),it is located on your exhaust manifold or silencer before the catalytic converter and it is responsible for sending input signals to the ECU(brain box) as regards quality of exhaust gas (oxygen really) which the ECU uses to determine air/fuel (A/F) mixture,do a data stream of the sensors and then check for continuity,also check your wire harness,if no resolution replace sensors.besides there are no such codes as P1135 & P1155 listed under toyota camry 04 manufacturer's trouble codes as they are not generic trouble codes.

Hi femicousim,pls can you send me ur email on smilesteve4sure@yahoo.com