Hi,

Off and on for a while now, I've been getting codes P0134 and P1157. P0134 specifically says Bank 1 Sensor 1 and P1157 refers to A/F sensor. How many total O2 sensors does this car have? I see 2 on the exhaust pipe schematic...would these be the REAR sensors? Would I have 2 more sensors on the FRONT side of the firewall? Would you agree I need to replace the REAR A/F sensor?

2006 Accord EX, 4-DR, 4-cyl, non-Calif. emissions. About 140K miles.

Thank you!

 

FRONT sensor.

There's 2 sensors total. Both are "bank-1" because the terminology of bank-2 is for the V-6 engines.

Both sensors are down low, but one is clearly upstream of the cat. The "bank-1 sensor-2" is screwed into the side of the cat.

The "A/F sensor" terminology is because your engine is new-enough that the front O2 sensor is a wideband sensor.

 

update...
I just looked at the parts schematic, & three are shown. But the rear-two are alternate sensor parts just because that parts drawing covers several years/models of Accord. The "front" sensor is just below the flange at the bottom of the 4-into-1 exhaust manifold. On the back-side of the engine, down low.

 

See image.