1131 lack of o2 lean bank 1

[mickey]

Now this is a loaded question knowing there are multiple things that can make a car run lean on 1 bank. Was wondering if there is something common to check first? Car is a 98 4.6l auto transmission

 

[DKblue98GT]

How old are your O2 sensors? I recently had the same issue. New upstream O2 sensors fixed mine...

 

[mickey]

They look original the car has 75,000 miles guess I'll take a closer look at them.

 

[kvoriley]

Any exhaust leaks? Passenger side manifold to downpipe gasket if bad could also cause a lean code

 

[mickey]

No leaks I checked that the other day when I got it