Misfire code Po300 and surge

Good evening,

I would start by checking the fuel pressure as this is the most common reason for a code 300. low fuel pressure will not provide enough fuel to the injectors for proper fuel mapping.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

How old are the tune up parts?

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



Roy

Where is the pressure regulator location?

The regulator is part of the fuel pump module in the fuel tank. it is not external.

Roy

Where on that diagram?

Would a vacuum leak do that too? Also, how to you swap the fuel pressure?

It is part of the pump.

you replace the fuel pump assembly.

no, a vacuum leak will not effect fuel pressure.

Roy