PO 139 and P0174 Honda -

Question

what does it mean to have both codes PO139 and PO174 on a honda accord

Answer 1

P0139 Rear secondary H02S (bank 1 Sensor 2 ) slow response

P0174 Front Bank 2 fuel system lean

You have a lean running condition, P0174 which affects the catalytic from performing its job.P0139. Lean condition can be cause by unmeter air that affects the MAP (manifold absolute pressure ) sensor  such as a slighlyt open EGR or even low fuel pressure, correct for the lean condition