Engine shut off while driving

Hello, sorry to hear about the trouble. It's odd for a Toyota to seize up. Can you turn the engine over by hand, by putting a socket and long bar on the crankshaft harmonic balancer? Also, what is the code number you have for the crankshaft position sensor?
What is the oil level, and did you hear any odd noises before it stalled out?

https://www.2carpros.com/articles/engine-stalls

Okay, hopefully it's just a loose connection somewhere in the wiring harness. If so, it's possible the Starter is just not getting enough voltage to fully engage and turn the engine over. Hope for the best. If you can turn it over by hand, do it a couple of times and see if you hear any odd noises. If all seems okay, then check the Starter motor connections and battery voltage to see if you have a multimeter available.

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

https://www.2carpros.com/articles/how-to-check-a-car-fuse

No worries, Whenever you get the chance.

I would just leave the negative battery cable off and pull the Starter first. But I would find it strange if the engine stalled out due to the crankshaft position sensor and the Starter motor also got jammed into the flywheel. But at least if you can get the Starter out semi easy, and you still can't turn the engine over by hand, you know you have bigger problems. If the engine seized or something happened with the timing chain, the Starter might have just gotten stuck because it couldn't move anything at all. After you get the Starter out, and if it won't spin by hand, you may want to drain the oil and look for any metal particles. It's also possible that something happened to one of the crankshafts, anything that would prevent the crankshaft from rotating. If you put the starter back in, I wouldn't try starting it by the key until you figure out what happened. If it has something to do with the timing chain, you will reduce the chance of more damage.

I hope so too, I would be surprised if it seized though, but it does happen. Let us know what you find.

So sorry to hear about that, I would be crying too. I'm looking up info for you right now, I think you're correct if you have plastic in the oil pan, sounds like chain guides to me, same thing as the bigger Ford engines does, but they all do it. This is a huge job for this timing chains, just by the little information I've seen already. It has four timing chains, two long ones that go to each cam and then two short ones that run from cam to cam. Yeah, the valve covers have to come off, but you have to be careful, in each valve cover there are two VVT sensors, a camshaft position sensor, and two oil control valves. I'll post what I have below, but I'm limited on resources this week, it seems the Mitchell database is down. But I'll do my best to find whatever I can. I was told it is an Interference Engine unfortunately. With the valve covers off you will get a better look at things. Do you have a picture of the plastic pieces that came out? I'd be interested to see if it's guides. Honestly I'm kind of surprised. Toyota in my opinion is one of the best brands, Tundra is my favorite truck actually.
As you can see in the first diagram, it's a crazy chain set up. There is also a TSB on being careful not to damage the baffles inside the valve covers when removing them, I guess they are pretty fragile. Diagram seven shows there are some type of valve cover spacers with a small valve filter.
The bottom (last three diagrams are the timing marks and chain links. Though I'm not sure how this is going to go if you can't turn the engine over by hand. The 10th diagram shows the a view from the back of the valve sprockets and the chain link marks back there.
11 and 12 are the main longer chain tensioners and then the two short cam to cam chains also have tensioners in between the two cam gears. So sorry for all this happening. I understand how frustrating this is.

I've talked to a couple other technicians about this, most are telling if it was a chain failure it will most likely need an engine. I very much hope that is not the case with yours. Since you didn't find any metal particles in the oil, and I would look really close, but maybe something can be saved here. It might not have had time for any particles to reach the oil pan since it shut off so fast. But I really do hope for the best. Keep us updated, we like to get an end result as to what happened. Thanks

At this point what I would do, and I'm not sure if you have a borescope, but I would pull the spark plugs and stick a borescope (one if those little cameras that has a little light on the end, hooks to your phone or scan tool or its own little screen) and take a look down in each cylinder. If there is piston to valve contact, you will definitely see it. This is the one I use, costing about $70.00. Most others are very expensive. But it is a must have tool these days for us. This way you don't have to pull anything apart. You can even see a bad head gasket with one of these inside a cylinder. There really is no other way to get a good look down into a cylinder head, you can't take any running measurements with a pressure transducer in cylinder, and of course at this point if you could run the truck, you still wouldn't want to. I can send you the link if you want.

I know it costs a little, but it's worth it, the time it would take you pulling everything apart, even just getting to the timing chains would take you all day. This way you can inspect each cylinder on both banks in half an hour.
Take some pictures too, you can store them with this camera. I'd like to see what you find.

https://www.amazon.com/Endoscope-Teslong-Inspection-Automotive-Waterproof/dp/B07QCMDJWL/ref=asc_df_B07QCMDJWL/?tag=hyprod-20&linkCode=df0&hvadid=416904651034&hvpos=&hvnetw=g&hvrand=9095428266414648231&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9009954&hvtargid=pla-780842289079&psc=1&tag=&ref=&adgrpid=96633975809&hvpone=&hvptwo=&hvadid=416904651034&hvpos=&hvnetw=g&hvrand=9095428266414648231&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9009954&hvtargid=pla-780842289079