If it's the P219A error, that's the one I had before.
It's one these things:
Bad upstream oxygen sensor
Bad downstream oxygen sensor
PCV valve is bad
EVAP purge valve is bad.
loose hoses
exhaust leak
bad cat
now for the bad stuff:
ignition system not firing correctly
Fuel injectors / pump issues
and finally: damaged pistons / rods.
the O2 sensors can be checked if you detach them and test the connections with a ohm meter.
Another thing that can cause this (not in my case) is bagging your car when it's just started, and it's cold out.
good luck.