If you're car hasn't been running good and you've done the usual stuff, you might want to check the vacuum hose going to the fuel pressure regulator.
Out of the 3 engines I've seen recently, all of them had minor to major cracking around the hose. It seems like this hose would deteriorate faster than others. I can see why as this hose has little to no slack with the tight bend/kink in the hose near the FPR causing it to further stress and crack.