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

AL514, I appreciate the correction and the advice. When I attempted to change the A/F ratio sensor. I found it was in a much more difficult area I was not prepared for.

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.

So, I replaced that O2 sensor and cleared the code. Started the car back up again and got a different code P1394. Again, nothing I find can really tell where these sensors are. Even the Hayens Manual book isn't really clear.

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

Wow, thanks for getting back to me so quickly.
This is an XL model. I have the picture of the tag on the side of the door if you think that will help.

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, I just wanted to let you know that I started having problems with my alternator. I ended up having to replace the alternator before getting to changing the oil.

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?

When I first posted about my situation, my son was driving the car up at Uni. He vaguely remembers if other lights popped up on the dashboard. So, when the issue with the alternator happened, I replaced it. I drove the car for a day with no "Check Engine" popping up until the next day when I was getting the things to change the oil. I have only been able to drive the car for half a day after changing the oil and oil filter. So far, nothing, however; I plan on driving the car around all day tomorrow.

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

So, four days ago, I was about to call my car problem fixed but the "Check Engine" light came on. When I went to check the reading, the same error code came up P1349. The weird thing is when I tried to start the car again, I had no power. Turned my car off and back on but not trying to turn on the engine and the gages jumped up and went down. Then the fuel gage did the same. The lights on the dash flickered so I tried to start the car again, nothing. I then turned the keys totally off and tried the auto remote start, but still nothing. I popped the hood to check the battery cables, since I had just replaced the alternator two days before, shocked the cables and they seemed to be on tight. Then out of the blue, the signal lights flashed and then the car started with the key turned off and me not touching the remote start. I wasn't sure if the power issue made the error pop up or what. So, I cleared it and drove for another day and a half. The 1349 error popped up again. This time no power issue happening. I decided to replace the Front and Back VVT solenoid and filters. The Back VVT solenoid was really difficult to move. The Front VVT was still moving freely. I just replaced them all. It has only been a day with some driving. I am looking to see how it drives for a few more days and see what these replacements do for the P1349 error. Still no power issue.

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.

When I said there was no power, I turned the key all the way, nothing came on and the car didn't start. Currently, there are no codes. It has been 6 days since I replaced the 2 VVT and 2 filters. The Timing Belt had been changed a few years ago. With any wire connections, there were 2 near the Air Filter and 2 near Throttle Body, but I was able to disconnect those and reconnect them without any problems.

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.

Yes, after when the Avalon didn't start then started a few minutes later. I haven't had a problem with the car starting. What do you mean by "in open loop operation (so cold star)?

I unfortunately had not been able to do the other Oxygen sensor. I also have to deal with my 1996 Toyota RAV4 Oil Cooler housing O-ring issue. I would love any additional help you can give on that if possible.

From what you had told me and what I looked up. This Oxygen sensor is underneath the car and I need to move/ remove the passenger seat to get to where the harness comes through the car frame.

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.

Okay, so it has been about a week, and I have not received another "Check Engine" light. I was finally able to get the right O2 sensor. I replaced it today and drove it for 15 to 20 minutes. Took a reading. Hoping I'm getting a better percentage. It looks like it is, but I wanted to post the latest reading.

(I have created another post for my 1996 RAV4. How to replace the Seals for the Oil Cooler Housing. I did get a little help but haven't received any for the past couple of days)

Al514, I wanted to thank you for all the help and Information you gave me for this project. I don't know much about cars but with help I can find my way around. I hope this Post might be able to help others.

Okay. So, you got to replace the rear oxygen sensor under the seat. But these readings are in Open loop operation while the engine is still too cold. Get the engine up to full operating temperature first, you'll know when the "Fuel System Status" reads CL. Thats Closed Loop operation and the ECM will be taking readings from the front AF sensors and the rear Oxygen sensor. I still see 0.0volts on the rear oxygen sensor. It should be higher than that. The 3.3volts on the front AF sensors (oxygen sensors) is just a biased voltage the computer puts out. The AF sensors work off of current flow and not a voltage reading. But the rear oxygen sensor is a standard regular oxygen sensor. So, I would expect to see at least 0.5volts on that steady once the engine warms up.

If these readings are after a 20min drive, then there is an issue with the thermostat or cooling fans staying, something that is not allowing the engine to get up to operating temperature. 177 degrees is too low. The thermostat for this vehicle should be opened 10mm at 203f degrees, if your scan data is not reading over 177f the vehicle is never reaching a temperature that can allow it to go into Closed Loop. And the Oxygen sensor output voltage (B1S2) being still at 0.0volts isn't correct.

It's possible you have a wiring issue somewhere, or a corroded connector, but 0volts looks more like an open circuit, where the signal is not even reaching the ECM. So, take it for a longer drive or allow it to idle for 30 min and then check the live data PIDs again. We need to get it up to operating temperature. I'm going to get the info together on replacing the thermostat. On your first post with live data, you had a coolant temperature reading of 192f but still in Open Loop. And I'm not sure why that scan tool is not reading any engine RPM at all.

One other thing I see is that you have 7 IM Readiness monitors and only 6 of them are complete. It's on the first data screen. Try pressing the I/M button and see which monitor has not run. The IM (Inspection/Maintenance) monitors are self-tests the ECM runs on the vehicles systems. They should all be complete. Any time they wouldn't be is if there is a problem (failed test) or if the battery has recently been unhooked and they haven't had a chance to run yet. I will also see if I can find where the rear oxygen sensor wiring runs, we know it comes into the vehicle under the seat, and the ECM is located on the passenger side behind the dash, so maybe behind the glovebox. But we need to see a voltage reading from that sensor. Unless this is something to do with the scan tool not giving accurate data. I have never used one of that brand before. But I know it's giving you global OBD2 data, and not manufacturer data. But Global OBD2 should be sufficient. Toyotas are more technical when it comes to their electronics. I think they are one of the better vehicles out there, but they are more difficult with their labelling of components and such.

But I would recommend getting a reading with some external temperature probe of the thermostat housing and see what you get. The thermostat might be getting stuck halfway open and/or not closing all the way.
That 2nd picture of the oxygen sensor looks like it possibly overheated, but my main concern is that you're driving around all the time in open loop where the engine computer is mainly calculating its fuel strategy on the engine coolant temperature sensor, when it should be taking data from all the sensors in Closed Loop, and it has to reach its full operating temperature to do so.

Again, sorry for the long post, I will also take a look at the Rav4 service info as well really quick, if no one has gotten back to you, you can post again, and it will show up as a response to the tech that was helping you. I'm not sure I will be able to find it being that far back. But I'll take a look myself after I get the thermostat information.

Take a temperature reading at the thermostat location in the diagram below.

https://www.2carpros.com/articles/how-an-engine-thermostat-works

I appreciate your post and all the information. So, I drove around a little longer and let the car idle for about 10 mins before I took a reading. I left the car running when I took the reading (the other readings I had turned off the car and turned it on before starting the car).

Okay, that reading on B1S2 oxygen sensor voltage of 0.7volts is what I would expect to see on that sensor, so that's good. If you press the I/M button with the key On, does your scan tool list which IM monitor has not passed yet? I'm just wondering if it's the Oxygen sensor monitor that hasn't had enough time yet to complete the IM readiness since you replaced an AF front sensor. You can see by the 1st chart it takes about 10 of these cycles to complete the Oxygen sensor monitors. The vehicle is running somewhat lean at idle.

I ran a VE test with your live data values and the Volumetric Efficiency was low. Being a 3.0liter engine, a rule of thumb is the Mass air flow sensor should be at about 3 grams per second at idle. Your vehicle is running at 2.65g/s, but since you haven't mentioned any running issues, this can be a vacuum leak, or an under-reporting mass air flow sensor. which would explain the low mass air flow reading and the high fuel trim numbers.

Bank1 is about +8.6 percent and Bank2 is about +10.9 percent. So, if these numbers don't come down after a while, looking for a vacuum leak will be next. If the Fuel Trim numbers come down at higher RPMs (2,000-2,500 RPMs), that points to a vacuum leak. The Equivalence Ratio (lambda) should be around 0. Where it's at 0.997 now. So, the front oxygen sensors are indicating a lean condition. But those fuel trim numbers are too high. Let's see if they come down some with some drive cycles. Cleaning the mass air flow sensor might help, auto parts stores carry mass air flow cleaner spray.

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

These are 2 sets of readings from 2 different days (04.02 & 04.08). I cleaned the Mass Air Flow Sensor as you suggested before I took the reading on 04.08.23. I also took the I/M reading as you mentioned. I took to 2 pictures of the Air flow rate of the Mass Air Flow Sensor. It seems to change when I highlighted that category.

Okay, I will go over these data PIDs and get back to you shortly. But I already see a huge improvement.

Okay, I've gone through all the data, and everything looks really great, the fuel trims are almost perfect, the Air/Fuel sensor voltages are great. When the MAF was at 0.47lb/min (3.55g/s), engine RPM 786, that's a much better Mass air flow reading, I'm just wondering at what point it went back down to 0.36lb/min (2.72g/s). How does the engine feel? Does it have good acceleration? For some reason the Volumetric Efficiency test keeps failing. But if you have full power back, and nothing is setting any codes. We won't worry about it too much. The only real reason I'd see it fail this test would be a restricted exhaust, but all the live data doesn't really point to that, unless you're noticing a performance issue. Even the Bank 1 Sensor 2 oxygen sensor voltage of 0.5v looks better. All 7 IM monitors passed so that's all good. I'm not sure why these VE tests are coming out like this. The 2.72g/s on the MAF at idle is a little low still, not sure why your data is jumping around like that. But with all passed IM monitors, we won't worry about it unless you happen to notice a lack of power. If the Converter is partially clogged, you would notice it on a wide-open throttle test. There would be a hesitation as if the vehicle was pulling a heavy load. But if it's okay, just drive it and we'll address any issues that come up in the future.

My wife and I have driven it separately and we both feel that the car is running well. We also feel like we get good and immediate reaction from acceleration. I plan to take a long drive and will take another reading.

AL541 I want to thank you for all the help and information.

It's no problem, that's what we're here for, I'll look into this VE test some more and see if there's a logical reason for it failing. I might try a different test as well. The VE test pretty much shows how well the engine breathes (takes in air and pushes out exhaust). Take a look at your air filter too. It's probably the most neglected part of the engine. If it has been a while, just change it out, they're cheap enough. So, if I have some epiphany about the test results Ill post them here. In the meantime, have a nice day.

Okay, I found the reason; the VE test needs a Wide-Open Throttle run and then input the recorded data at the highest RPM. So, at idle the test is not enough data. So, nothing to worry about.

Okay, sounds great. I have never heard of or done a Wide-Open Throttle run. Any instructions?

I wouldn't worry about doing it at all. You would need to be recording live data at the same time, and you have to be extremely careful. So, disregard that test. The live data all looks great. So, no further testing is needed right now. The MAF cleaning helped a lot. A WOT test is something a technician should do, plus I don't want you to get a speeding ticket. Just let us know if you have any other problems in the future.