P0300 vehicle does not support it? She has had a problem with it starting?

Hello,

The code P0300 typically means that the on board diagnostics is unbale to connect with the powertrain control module.
Many times that code is related to the crank positing sensor not providing correct data to the PCM.
I have attached the step by step diagnostics for the P0300 code.

An engine could have lifter noise at start up if the oil pressure takes longer than usual to build up. As the oil warms up the pressure increase and the noise goes away.
It could be for a weak oil pump.

https://www.2carpros.com/articles/high-or-low-engine-oil-pressure

This noise can even happen if the incorrect viscosity oil gets used. As the engine ages usually that lifter noise increases as well.
What weight oil are you using?
There is a oil pressure regulator valve, if it gets clogged it can impact the oil pressure and could trigger the noise. That valve is located inside the oil filter housing (see below diagrams of the valve)

Please let me know of any questions.

Thank you.