Torque Codes for O2 sensor error?

Hello, what you're looking at is Mode 6 Data, mode 6 data was originally programmed into engine computers for engineers to determine how well systems are working with the current settings, but we do use it now as Technicians for diagnostics since information on the data displayed became available. These are self-test results and not actual Diagnostic Trouble Codes. So, for example, the TID (Test ID) 04 and then Component ID 20 is a self-test of the Catalytic Converter efficiency which is monitored by the oxygen sensor after the Converter. Its self-test reveals that the Converter has low efficiency, but not low enough to set a P0420 or P0430 which are OBD2 diagnostic trouble codes for the converter.
The other Test ID is for the EGR valve decel test, So the EGR valve may have some carbon build up on the valve itself or the pipe leading to the exhaust. They tend to get carbon build up in them over time and with the age of the vehicle, you may want to take the valve off and inspect all the passages from the exhaust to the intake manifold. With the age of your vehicle there will most likely be carbon build up. This monitor looks like it monitors the mass air flow sensor while activating the EGR valve for any change. I will post some more information on the mass air flow sensor if your vehicle has one. I have not looked at the wiring diagrams yet for the vehicle.

So, I dent see a Mass Air flow sensor for your vehicle, which means it monitors intake manifold vacuum using a MAP sensor, and the engine computer will monitor the map sensor when activating the EGR valve and watch for a pressure change. But just because these self-tests are not within limits doesn't mean you will fail the emissions test. If the check engine light was on then you would,

Some things you can do is check the throttle plates for any carbon build up, check the EGR valve and passages for carbon. You can also pull up the live data on your scan tool and see what the voltage of the rear oxygen sensor is doing. A slow oxygen sensor can cause self-tests to fail as well.
The rear oxygen sensor has a heater circuit built into it; the heater gets the sensor working faster on cold start-ups.
The front oxygen sensor on this vehicle does not have a heater, so it relies on the exhaust gases to heat it up and this takes longer. Checking the voltage levels of that sensor as well is a good thing to do. It should have a fluctuating voltage of around 0.2volts to 0.8volts. About a 1-volt swing.
Here are a few guides to help understand each system.
With the App you're using, look into the Global OBD2 side of things. I haven't looked at the Torque app in a long time, so I'm not sure why it led you to the Mode 6 data instead of the OBD2.
One last thing, the Lean-to Rich Sensor threshold voltage is just above the minimum, so the Oxygen sensors are looking like they are due for a change. It is passing the monitor, but just barely, they get lazy and worn out like every other part eventually. Hope this all helps.

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

https://www.2carpros.com/articles/how-emission-control-systems-work

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

I understand, I did notice you have pretty low mileage for a 1999 vehicle. There are a couple issues with letting a vehicle sit too long, the gas in the tank will start to go bad over about a year or so. Thats one thing to keep in mind. Getting some fresh gas in it every once and awhile will help, as well as adding some dry gas to help with any moisture/condensation that has built up in the tank. And condensation will settle in the bottom of the tank because water is heavier than gas. If it's going to sit for such long times, starting it and letting it get up to operating temperature, and then going for a 15-minute drive around will help. Thats better than it sitting for a month and will also use up some gas in the tank. That way you'll kind of be forced to get some fresh gas every once and awhile. Fuel injectors tend to stick closed on vehicles that sit along time. I remember a vehicle that had sat for an entire year, it was a V6 I believe, and all 6 fuel injectors were stuck closed. They get a small amount of carbon build up on the tip and the opening on injectors is very small. And the carbon had either hardened up, or it was the gas in the fuel rail, but they were all stuck closed. And I think tapping on them actually got some of them to start working. But they all needed to be replaced at that point. An auto parts store may also have some type of gasoline stabilizer you could add, although honestly, I have never used it on a vehicle before, so you would have to ask at the auto parts store about that.
And the last issue I have seen a lot is rodent damage to vehicles that sit, the like the taste of whatever chemical is used in the wiring insolation. And they will chew up and eat entire sections of wire. I worked for a Subaru dealership out in the country, and we would be removing rodents nests all the time. Most of time we found them dead in the blower motor for the heater systems. But the entire HVAC would need to be disinfected from it. Not a fun time. As for your oxygen sensor voltage, the front oxygen sensor, which would be labelled Oxygen Sensor Bank 1 Sensor 1, or 02B1S1. Should have a fluctuating voltage around 0.2volts to around 0.8volts, so a 0 to 1 volt swing constantly. The rear Oxygen sensor B1S2 should have a much slower voltage swing if any at all. I'll put some info on the oxygen sensor performance below. Most of the time, when the rear oxygen sensor voltage tends to mirror the front oxygen sensor voltage, which is a sign the Converter is not working efficiently. The Converter is not storing oxygen like is supposed to, to help burn off the excess hydrocarbons, and in turn putting out clean exhaust. A byproduct of this is actually H20(water), This is why you will see exhaust mufflers dripping water sometimes. That is a reaction of the Converter doing its job. But if you happen to fail your emissions test, let us know, and you can post your info here on what it failed for, and we can try to help you figure out why. California has much higher emissions standards than any other state by far. Putting some fresh gas in before you go for your testing will help. Old gas can cause cylinder misfires and high CO, and high Hydrocarbons (unburned fuel) out the exhaust. I know this was a long post, sorry for that, but just some things to help you get through the testing ok. If you have any issues let us know, we'll help where we can.

https://www.2carpros.com/articles/how-emission-control-systems-work

https://www.2carpros.com/articles/smog-test-inspection-information

Thanks for the update. These are actually really good readings, HC (parts per million) is the Hydrocarbons which is raw fuel at an average of 9 out of max 66 is great. CO Carbon monoxide partially burned fuel 0.03 percent is really good as well, And the NO (Nitrogen Oxide) which is a gas produced by very high cylinder temperatures is low as well. If you ever Fail an emissions test for NO, then check the EGR Valve, its responsible for keeping these gases low. But those are the 3 we would be worried about. The C02 is water vapor and 02 is Oxygen. So, it looks like the engine is running really well. I haven't seen one of these emission test result charts in a long time. Modern vehicles have so many sensors now, most of the time they just look for the Check engine light being on or not. Glad it went well for you.