Is bank 2 sensor 1 upstream or downstream?

Sensor 1 is always upstream (before the catalytic converter). Sensor 2 is downstream (after the cat).

Why does my V6/V8 have bank 2 codes?

V-engines have two exhaust banks. Bank 2 is the opposite side from cylinder 1.

Medium Severity

Emissions System

General fault with the upstream O2 sensor on bank 2 of a V-engine.

Common Fix

Replace upstream O2 sensor bank 2

Estimated Cost (DIY)

$30 - $100

Faulty O2 sensorlikely

Exhaust leakpossible

Wiring damagepossible

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Is bank 2 sensor 1 upstream or downstream?: Sensor 1 is always upstream (before the catalytic converter). Sensor 2 is downstream (after the cat).
Why does my V6/V8 have bank 2 codes?: V-engines have two exhaust banks. Bank 2 is the opposite side from cylinder 1.

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