Once again, I've reviewed the whole thread,
Getting it all straight in my head.
It'* not happening all the time, forget the compression test,
Time to begin trying all the rest.
I'd get a real scantool on the car,
before you go too far.
Your SC also does need some help,
before you drive to get some kelp.
Sorry. That'* all I could think of that rhymed. Compression is out, since this doesn't happen all the time. The cat could still be possible, and the PCV, too, but that'* a remote chance. It'* time to get a real scantool on this thing and check it out. Do you have one available?