I'm looking to buy the two downstream O2 sensors for 2003 Honda Civic Hybrid, preferably Denso:

(non-CA emissions, CVT)

I see Denso lists several options for me:

From http://www.densoaftermarket.com/cata....php?part=o2sn
Air Fuel Ratio Sensors (this is the upstream, sensor, right?)
HYBRID 234-9005 (Air Fuel Ratio Sensor)
Exc. Calif.; DENSO is the O.E. Manufacturer / Air Fuel Ratio Sensor 1 Upstream OE Style

HYBRID 234-9005 (Air Fuel Ratio Sensor)
Calif.; To Eng #3S020135; DENSO is the O.E. Manufacturer / Air Fuel Ratio Sensor 1 Upstream OE Style

HYBRID 234-9005 (Air Fuel Ratio Sensor)
Calif.; From Eng #3S020136; DENSO is the O.E. Manufacturer / Air Fuel Ratio Sensor 1 Upstream OE Style

Oxygen Sensors (these are the two downstream sensors--replacing Honda 06365-PZA-A00 which do I need?)

HYBRID 234-4224 (Oxygen Sensor)
Exc. Calif; Loc. After Primary Cat; Exc. Calif.; O.E. Quality Replacement Sensor 1 Downstream OE Style

HYBRID 234-4352 (Oxygen Sensor)
Calif.; From Eng #3S020136; O.E. Quality Replacement Sensor 1 Downstream OE Style

HYBRID 234-4355 (Oxygen Sensor)
To Eng #3S020135; O.E. Quality Replacement Sensor 1 Downstream OE Style

HYBRID 234-4613 (Oxygen Sensor)
Exc. Calif.; Loc. After Secondary Cat; Exc. Calif.; O.E. Quality Replacement Sensor 1 Downstream OE Style

HYBRID 234-4210 (Oxygen Sensor)
Exc. Calif; Loc. After Primary Cat; Exc. Calif.; O.E. Quality Universal Replacement Sensor 1 Downstream Universal

I replaced all three O2 sensors 60k miles ago with Honda parts (have 140k on the car), now I'm looking for a cheaper route that hopefully won't affect my mileage.

Thanks,

Tim