Random misfire and codes P0300, P0303 and P0304

Hi,

These codes can be the result of a few things. Engine vacuum leaks, fuel pressure, along with other things can cause them.

Since the vehicle only had 74,000 on it, I can't imagine it is a compression issue. So, lets start by checking to see if there are any leaks that could be causing it. Here is a link that explains how to check for engine vacuum leaks:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Also, make sure the air induction tube between the air box and the throttle body is properly installed.

Let me know what you find

Joe