Valve adjustment for a 2007 Toyota Yaris. When (mileage wise) if it necessary to address the adjustment of the valves to avoid wear and tear?

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Should have hydraulic lash adjusters . But valve clearance needs to be set during engine assembly .

First find where it is coming from. Most likely from the valve covers. Just wear and tear on the components. I believe Toyota has adjustable valves. You'll have to remove the valve covers. The rockers arms will have a screw with a nut on the top of them. Loose the nut and adjust the screw down. This has to be done with each cylinder at top dead center. You will need feeler gauges. The gap is small. 3 to 7 thousandths. I don't have the exact numbers. The intake and exhaust valves are different measurements.

Camshaft Position Actuator Circuit (Bank 1)

its a variable valve timing (VVT) code. You'll likely need to take it in for diagnosis.

Possible causes include: Faulty oil control valve(OCV), open or short in VVT circuit, damaged pcm, open or short in the OCV/solenoid valve

IT will have hydraulic tappets and no adjustment is necessary . It is making a tappet sound then at that mileage I would be inspecting the rocker bushes and shafts for wear as this is a Mazda problem when the engine s get old. Replacement is the best option.

Engine stalls soon after starting
1. Fuel pump control circuit.
2. Spark plugs.
3. Ignition system.
4. Fuel Injectors.
5. Variable valve timing system.
6. Electronic throttle control system.
7. Air induction system.
8. PCV hose -
9. Compression

I have an automatic Toyota Yaris 2007 The clutch is going What causes this as mileage is very low and how much would it cause

Many things, depending on sensor. Some wear out with mileage (oxygen sensors etc...) Others from bad fuel, lack of maintenance...

Some easy things to do, a new air filter, some fuel injector cleaner in the gas, Check the PCV valve, New spark plus, and wires if they look questionable.

This should get you back in shape, anything else would need a mechanic to get involved

the possible causes are: alternator low charging, check valve at the valve cover not working.