Just a guess, but...
...perhaps your idle mixture is too rich?
...catalytic converter is clogged?
...O2 sensor is picking up some chemical byproduct as a result of the plastic bag residue still burning on the cat?
Not sure whether those conditions will send a warning, but it's a thought...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car