1998 Ford Taurus Engine shudder and rough idle -- throws p0

For a while the vehicle has been idling rough at a stop and I suspected but never searched out a vacuum leak. Today the vehicle began to shudder pretty bad both on the road and at an idle and the check engine light began to flash which I've never seen. Instead of surging at idle then falling to almost dying it would continuously idle very poorly. Acceleration was extremely poor and when I got home there was a definite smell, a little bit like burnt popcorn. Now i'm just worried its a little more than a vacuum leak. OBD scan showed p0133, p1131, and p0302. Thanks!