My check engine light is on but the engine runs fine, but I seem to be getting poor gas mileage and very occasionally it will stall when stopping at a traffic light.

I'm getting
P0130 02 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P2198 - O2 Sensor Signal Stuck Rich - (Bank 2, Sensor 1)

Sorry, I'm not super knowledgeable about engines, but since the codes are from BOTH banks I'm thinking that odds of both sensors being bad is very low and the problem is likely something upstream before the 'split" into the two banks because a problem in that area would explain faults in both banks...

Any thoughts of what could be causing this? Again, my check engine light is on but the engine runs fine, but I seem to be getting poor gas mileage and very occasionally it will stall when stopping at a traffic light.

Thanks!

 

I also believe the O2 sensors are just doing their job and indicating a fault from something else.

How can anyone help you without any vehicle information????? Proper communication gets problems resolved.

 

Another first poster who posted and ran.Why do they waste their time and everyone else's.

 

If they were all perfect like us, who would we seem intelligent to?

 

OK, so I finally had a chance to snoop around. As mentioned, I was getting oxygen sensor errors on BOTH banks of my 4.6L 2011 engine so figured I'd look upstream of them to something that might cause both to trigger those codes.

I took off the air cleaner assembly and noticed that the rubber gasket seal for the wires connecting to the MAS was not inserted into the air cleaner assembly, but just hanging loose as can be seen in the photo.

I'm not sure if that rubber gasket is merely to hold wires in place or actually has a more important job and supposed to be creating an airtight seal - and since it was hanging loose and leaving a big hole could be creating the errors?