Faulty O2 Sensor P0300 alone with Secondary DTS P0301, P0303, P0305 and P1130?

Hello, this is not an oxygen sensor, it is an air fuel ratio sensor on Bank 1. So, it is the front sensor in the exhaust on the side that cylinder 1 is on, which is why you are getting misfire codes for Bank 1 cylinders 1, 3, and 5. Bank 1 is the back Bank of cylinders if you're facing the vehicle. It will be the sensor in the exhaust on the back side of the engine. I'll post a diagram for you as well. You will have to clear the codes out after you replace the sensor as well. The air fuel ratio sensors look like oxygen sensors but work on current instead of voltage like an oxygen sensor would.
This is the only sensor you need to replace. You can identify it by its wiring colors. There are only 2 AF sensors upstream of the Catalytic Converter. But with the cylinder layout as you see in the diagram 1, Bank 1 is the back row, once the codes are cleared and the sensor replaced the other codes should hopefully not come back.

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

Yeah, the ones in the back like that can be difficult, they make oxygen sockets that are helpful they will fit around the wire harness, and you can put a ratchet on it. It also makes it easier if the exhaust is hot, because the exhaust pipe will expand around the AF sensor, you just need to wear gloves, so you don't get burned on the exhaust pipe or anything. But if you haven't gotten it out yet, just ask at your local auto parts store if they have oxygen sensor sockets and pick one that will fit well for that location.
Oh, and make sure to erase the code after you replace the sensor, or the ECM might not turn the heater circuit on. I had that on a Toyota once, I would erase the code and start the car, it would turn the oxygen sensor heater on for exactly 10.6 seconds every time then disable the circuit to protect the ECM.

Okay, I'll look up that code setting criteria for that one, in the meantime, because of the rich running condition and misfiring cylinders, do an oil change, When you have that many cylinders misfiring the oil becomes contaminated with gasoline blow by, It's the unburned gas that gets pushed past the piston rings and ends up in the oil. So do an oil change with filter first, then reset the codes and see what comes back, it might not be anything to do with the variable valve timing. Those components are controlled by oil pressure and with contaminated oil, the oil is now diluted with gas. You might even pull the oil level stick out and see that it's above the full line. Either way change the oil, reset the codes. They might not even come back, but I will post the information on them just so you have it in case. But you had an entire bank of cylinders misfiring. Thats 3 out of 6, the oil is absolutely diluted. It will actually cause another rich running condition because the PCV pulls from the crankcase where the oil is.

Is this Avalon an XL or XLS?
And one other thing before you erase the code, can you pull up the Freeze Frame Data that came with that code. It's the conditions of the vehicle's sensors during the time that the code sets, I just want to look it over and make sure there is nothing else that looks out of place. It should be an option if you back out of that screen you're on with the code.
One of the first things service info mentions about this code, is oil pressure. So, I don't think you have a valve timing issue. I really think this is an oil pressure issue right now. This is a result of the bad AF sensor, just make sure you put the correct oil type and filter on. I put the oil info below as well. Let the oil drain out for a while. You want to get as much as possible out.

If you want to test the VVT solenoid for that back Bank of cylinders, the VVT solenoid is a 2-wire connector, and you just unplug the solenoid and check the resistance of it with the engine off. It's probably okay, but this way you can verify the solenoids integrity. The solenoid should test at 7 to 8 Ohms at around an ambient temperature of 70f degrees. But I think the oil change and then erase any codes, should take care of the issue. If any codes come back let us know. Hope this works out well for you.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

It's okay, the wiring diagrams are the same but try the oil change and filter first. You might not have to do any testing at all. Every engine has blow by gases passed the piston rings, even perfect running ones. So, I'm hoping a good ole oil change should help it out and take care of that code.

Hello, did you have any success with the vehicle so far? Let us know what ended up being the fix for the secondary code. It will help others in the future. I would also recommend taking a look at the spark plugs in that rear cylinder head. For the cylinders that were coding for misfires, 1, 3, and 5. Since it that entire engine bank was having so much trouble, checking them that they are not all full of carbon deposits is not a bad idea. With it running correctly though they should eventually burn any excessive carbon off. But knowing if the oil change took care of the vtec solenoid code would be great, if it happened to fail and its resistance test failed, that would be good to know. Thank you.

So, you had 2 faults occur back-to-back. Did you have a Battery light come on after the first repair? But the oil change did take care of the VTEC code?

Okay, I understand what you're saying, I was just wondering if it was possibly a low voltage issue that caused the VVT solenoid code to show up, but it seems to have set again even after the Alternator was changed out. It's strange how components fail a couple at times like this, but it happens more than people think. But if the VVT code comes back after you have driven it around for a day or so, along with checking the resistance of the VVT solenoid unplugged (7 to 8 ohms), you can also check for power with the key On engine off, it looks like the Red wire with a Black stripe should be the power feed wire. Toyota provides a waveform when testing using an oscilloscope. Service info states with the key on you will have this 0v to 12v square wave signal, but I think this info is incorrect. I don't think there will be any pulse width modulation of the solenoid with the engine off. I can't see why the ECM would be activating the solenoid with the engine off. So, there should be 12volts steady on the red/black wire. Thats another check you can do. If the resistance test fails though at 70f degrees temperature, just replace it. But hopefully the oil change will clear things up for you. Let us know if you need help with anything else.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Okay. So, this can't all be related to just that code then. When you say you have no power, are you getting to a certain rpm level and the no further? Sounds like it's in Limp Mode or some kind of reduced power. The fact that it started by itself, sounds like the remote start signal got delayed for some reason. I would stick to steering away from the remote start for now until we figure out what is happening here. Is 1349 the only code right now?
The cluster issue might be a module or communications failure happening. I'll look through the information Bus and see if any particular module is a Gateway for the rest of them. It was good you replaced the VVT solenoids, at least we can rule those out now. The old ones look pretty beat.
Let me look a couple things up.
ok the info on your scan tool says it can read live data, I would pull up all the live data so we can see if there's any skewed readings, I would also check the Battery voltage with the vehicle off and then check it again with it idling. First check the DC voltage while running, then check the AC voltage while running at the Battery. Let's see if the new Alternator is sound first and not putting out any AC ripple voltage. You should read less than 1volt of ac voltage, actually should be below 0.5volts, but let's verify that first.

Then with the vehicle running on DC volts, check from the Battery negative to the Engine Block, and then also Battery Negative to the Body (frame). Let's see if there is any voltage drop on the Negative side. Turn the headlights on while doing all these tests so there's some load on the electrical system.
I don't like the 10 percent on the Long-Term fuel trim for both banks. I don't like either, that is the limit I would allow. And when the code is set, you're doing only 21MPH but have 42% engine load, is about 1,500 RPMs the highest it will go?

https://www.2carpros.com/articles/how-to-use-a-voltmeter

After reviewing this entire post again, I'd like you to take a look at the live data for the Bank 1 sensor 2 Oxygen sensor voltage reading, if you can graph the reading with your scan tool that would be even better. We need to know if the voltage for that sensor is fluctuating from about 0.2volts to 0.8volts? Or if the voltage reading is steady, the Bank 1 sensor 2 is the only downstream oxygen sensor (after the catalytic converter). Now that both banks are reading a positive fuel trim numbers, we have to see what the rear oxygen sensor is doing, it is most likely related to the lack of power. I'm surprised no other codes have set yet, they might still. It's very strange that the VVT code took 4 days to come back.
It's possible there are corroded connectors, Toyota has a bunch of bulk junction connectors, most of them are for Ground locations, but see what the Bank1 sensor 2 oxygen sensor is doing first after the vehicle is up to operating temperature.
Have you had a timing belt service done on this vehicle yet? I'm not saying the timing is off, there's just some strange random things happening here. With the Cluster acting strange and what seems like the security system inhibiting start up delayed like that, I would think a wiring or module failure sending out corrupt data intermittently, but it's difficult to say, unless something finally just fails altogether. We should check some of the wiring Junction Sections for corrosion or loose connectors. I will post their locations. There are a few on the passenger side, lower dash right kick panel, so where the passenger's right foot would be. There is also a couple on the driver side behind the left kick panel.

Note: When you changed the AF sensor for the 1st code you had, you must have had to move some things around, since the sensor was difficult to get to. With all these other things happening after you changed that sensor, I would retrace my steps here. There must have been a bulk connector, or something that got moved around, was the wiring harness pulled on at any point to get it out of the way, because there's too many faults occurring that were not there before. And that solenoid that is setting the code now is on the right side of the engine as well (back side). There has to be something in common. That code set right after the AF sensor replacement.
The Green mark below is the B1S1 AF sensor, the red mark is the VVT rh solenoid that's coding.

So, it's running now? How did you get it running in the videos? The only thing I see in the data is the system is still in open loop operation (so cold start). Both front AF voltage readings are correct, the lambda reading of 0 is correct. The only thing that looks off is the Oxygen sensor B1S2 reading 0 volts is not correct. Charging voltage looks good.

The Open Loop operation is on cold start up, it is when the ECM is adjusting the fuel strategy mostly based on coolant temperature. Once the engine warms up, the oxygen sensors warm up, the vehicle will go into closed loop operation and use data from all the other sensors. Yes, the Bank1 sensor 2 rear Oxygen sensor connector is under the passenger seat. The voltage reading of 0volts is concerning. Sometimes if the wire for the sensor that runs through the grommet gets pulled on and the wiring makes contact with the frame, it can short out either the sensor wiring or the heater wiring which all runs through the same grommet and connector, that's what the 4 wires to the sensor are for. You might be able to check if the grommet is still in place, and possibly reach under the seat to check the connector.
With that rear oxygen sensor reading 0volts, that is a lean signal to the ECM and might explain why the Long-Term Fuel Trim numbers are going positive on Bank 1 6.3percent and Bank 2 13percent. The 13percent is too high, anything over 10percent is not good.
I don't know if that sensors voltage reading changed at all after warming up, that's something to monitor.
As for the Rav4 situation, you will need to post that as a new question. We are asked to have different vehicle issues start a new posting. So, we try to follow the rules of the site. Sorry about that. Someone will help you with that promptly.