Recommended from another forum:
"quick test. With the engine running, open your oil filler cap. Is there smoke coming out or can you smell fuel? If so, you blew up a piston. This happened with my last car and you can check this way.
If you do smell fuel/see smoke, do a compression test immediately just to verify."
Just did this test. No gas smell to my nose. No smoke. Does the engine have to be hot?
Still P0301 and P0303 and rough running.
The exhaust smells gassy.
I also sprayed starting fluid around the intake tract and other hoses with no noticeable increase in rpm.
I guess its back to one more swap of the coils and a look at the newly installed plugs... :-(