My shops experience with this code is always due to a stretched chain. Which usually we find out after talking to the customer they were not very good at getting oil changes done on time.
Not saying this is your situation.
Chains for the most part do not need to be replaced. We have plenty of high mileage Toyota's with chain motors that are all original and run fine.

The new crankshaft sprocket gives an increase in diameter of .003”.

That's good info, thanks. I'm in the middle of a timing set replacement on my '07 4Runner due to chain stretch and chronic P0016, got new Toyota chains, sprockets, guides, and tensioners. Sprockets being replaced are the exhaust cam pieces, crank, and idler.

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Feel fortunate it's not an older GM product.
Timing chain replacement was common by 70k.
At least it's an easy job.

I had at first intermittent P0016 A bank correlation errors, then it was solidly on for about 20,000 miles.

Finally got up the courage to tackle the timing chain job. probably took 30 hours to do. (Around a week of evenings and a solid weekend). Things got allot faster as I accumulated more tools (different length extensions mostly!)

I have changed the oil, and brakes on vehicles, but that's about it. Its not very hard, but it was helpful to refer to the service manual.

You can do it, Just not if its your only means of transportation.

I recently did the chain on my 04 V6 with all Toyota parts and it runs fine but throws a P0012 code on close inspection I think I may have my cam chain on the passenger head one tooth off. My challenge is I can't get the marks to line back up so I can check the cam chains. The primary seems to be fine but I can get the cams to be in sync. I had this same probably when I double checked my set up but after multiple turns of the engine everything lined up. After driving it and the code I went back in and can't get it even close, I know it's not far out for several reasons, one I've been building domestic V8s for 40 years and I couldn't have made that big of an error (and I don't drink) and more importantly, the amount off it seems to be would result in catastrophic failure and it's ran fine for close to 200 miles. So how many complete turns of the engine is necessary for the marks all line back up? Domestic V8s, 2. sorry to clutter the thread but if someone was trying to check to see if their chain was stretched this would be a relevant question to this thread.

Thank you, any help appreciated.

I started my own thread for my questions but I'll supply the answer for anyone that runs across this thread.

The answer was 2 revolution as I am use to for the engine to end up back where you started, however it can take 20-30 revolutions to get the painted links to line back up. The set up can be verified by the marks/dots on the cam gears and of course the balancer. The painted links are mainly there as an add in the initial set up.

How many miles and years?

It's 04 with 355k+, in my thread I posted the conclusion. It ended up being a bad brand new variable timing sensor, the diag tree I used had sensor as the last choice and of course I assumed camshaft position sensor but my son mentioned the timing sensor would cause it. I walked through the diag tree on the other thread. Thanks for the response.