"Engine System Service Required" Code 042

[vorbosh]

Early in the morning found myself driving through a foot of water even though I should have known better. Enginge stalled but restarted after a couple of minutes. Water almost certainly entered the tail pipe. Afterwards the engine runs rough but does not stall.

The "Engine System Service Required" code comes up with the corresponding 042 code when I hold down the trip but for 15 seconds.

There is a posting on the web that this relates to the oxygen sensor malfunctioning. Could someone confirm that this is accurate?