'93 300ce

On my 09 ML320 BlueTec I got a check engine light with the fault code of 141400, from my iCarsoft MV V2 scanner, " The oxygen concentration in partial load operation is unreasonable (too low)" when driving in slow traffic today. I wasn't able to find what this might be related to. It did clear, any ideas?
Thank in advance for your help.

Maj. Dundee

You should investigate G3/2 (O2 Sensor Upstream of CAT) for damage or elec. connection.

'93 300ce

Thanks. The fault code hasn't returned. I'll check the connections. Can you tell me how you found these writeups in WIS. I have a subscription but I don't know how to look up faults codes. Thank you again.