I have a 2000 tundra and it knocks on startup. I spoke to Toyota and they said a high milage engine can have piston skirt issues. They get thin and cupped but it is not a fatal problem and he said just let it quit knocking before you drive it. Lower milage engines can have sludge on the valve guides and this will cause the valve to knock (the valve is not opening all the way and causes it to knock when closing) He said to get some bg's oil additive and it would probably clean the valve guide after a few days and quit knocking. Hope this helps.
ford Taurus Nissan titan, thundered trail blazer, Tahoe Toyota tank, tiberaun, Toyota tundra, transam, and many more
You have another problem other then the knock sensor if the engine will not start and run. A knock sensor will not cause the engine not to run.
Some cars will knock for th first minute or so on a cold start until the oil starts to circulate through the engine
Worn main bearings sometimes knock when cold starting
On the 4.7 liter 2007 Tundra: Put the trip odometer to "A" Trip. Then with key OFF, push trip odometer button and hold it. Turn key to "ON" but do not start the engine. The Odometer should flash a series of dashes. That's it, you are reset.
I have a Toyota with the 22r engine and it will start when its cold but it when it gets worm it wont start with out help
Often a knock when cold is caused by piston slap, which is pistons rocking in the cylinders until they expand in size when the engine warms up.
2005
T-100 in year 2000
Wikipedia shows the Toyota AR engine with roller rockers started in 2008. This particular engine has many low friction benefits to it.
start the engine if it runs its good