Might as well get that out early, since I see a lot of posts asking about info just like that.
Hooked up a OBD-II scanner and took my car for a drive. It's been basically knocking whenever you need power before the tranny kicks back and it gets higher RPM, which screams to me that it's lack of fuel.
Normally I noticed between 39-45psi, however, when this noise started, I noticed a drop to about 33psi. I've replaced the fuel filter already, and it got just a tad better. So I figured it'd be the fuel pump and or dirty injectors. Anyone else experience anything like this yet?