Will fail inspection in NYS for CO2 sensor / Fuel gauage not working stays at Full notch. What is the fix for this

Have you had the ECM checked?

The ECM controls your fuel to air mixture as well as monitoring the CO2 levels.

Also, have you checked the oxygen sensor, when there's too much oxygen intake,,, the ECM increases fuel to compensate for the excess air, and thus results in more CO2.

Another check would be to find the diagnostic port, (usually under the dashboard), and, to either hire, or borrow an OBD diagnostic tool and see if there is an error code displayed, beginning with 'P', the code will show you what component is likely to be in error for producing the high CO2.

bank 1 oxygen sensor needs replaced. also know as upper oxygen sensor.

OBD2 works for getting codes causing check engine light.
Cannot communicate to NYS DMV to receive inspection.
It will pass inspection. No check engine lights or codes. Problem is communication with inspection machine.

I still do not know the answer to the problem.

service engine light on Nissan will not damage the car in any manner, however you gas mileage may change slightly. Service engine light can be numerous of issue. Fist I would change the Co2 sensor, 99% that will be the main issue, most people don't realize that unit need to be replace every 50-75k miles. if that does not solve the issue than take it to the dealership and have them plug it into their computer and it will spit out a code so mechanic can narrow drown on what need replacing. Running bad gas or running low octane can also cause the light to come on. Before you change Co2 sensor, go to Mobile, Shells, Speedway, gas stations and put in 93 or highest octane gas and go to Automotive store and pick up a STP fuel injectors cleaner, mix it with full tank of gas and run it til next refill and see if that light goes off, if not than change Co2 sensor. I believe that truck has 2 sensor if it a V6. the sensor located on the exhaust pipe before catalyst converter. its easy to fix and replace if you have the tools. if you don't know where the sensor looks like or located on the car, just get the new parts and look compare the old to the new. they run somewhere around 35-40 bucks each. Co2 sensor measure amount of burned gas telling the computer if its running rich or lean, if the sensor goes bad the computer get trip and the light comes on. good luck!!

what were the specific inspection details like Co, 02, CO2 and NOx readings?

furthermore, have you done any maintenance like fuel filter, oil change and spark plugs?

check first the guage indicator,,,if its good,,, full down the fuel tank and check the fuel gauage sending unit(fuel level sensor) is attached to the to the fuel pump control module..

Change EGR. If that doesn't work, change Camshaft Sensor and Crankshaft Sensor.

If it is using any oil, I would replace the valve seals. That can cause a failed test.

The best thing to do is go to Auto Zone and get your Hyundai scanned for a DTC code. That would tell us which O2 sensor has gone bad. You have three O2 sensors and one of them has gone bad, the O2 sensor sends signals to the ecm to control the air fuel mixture so it will not run to rich or to lean which is causing you to fail the state inspection. Good luck and keep me posted on what the DTC codes are, be glad to help.

Yes it matters to the inspector, if it's standers part or after market part that was added and not functioning. They can fail it, I had Off road light's on my truck and one did not work but it was illegal to use them on the road i still failed my inspection till i replaced the bulb.
I ended removing the light, didn't feel like driving off to replace the bulb and come back to get it inspected again.
Good luck and hope this helps, guess it depends on how strick the inspector is.