P0160

P0160 means the bank 2, sensor 2 O2 sensor has shown no activity — the signal voltage has been stuck flat (within plus or minus 0.05V of bias for longer than the ECM's no-activity window, typically 60-180 seconds during closed-loop catalyst monitoring). This is the bank-2 mirror of P0140 and is electrically distinct from P0156 (B2S2 circuit fault) or P0157/P0158 (stuck low/high) — P0160 specifically says the sensor is connected but the voltage is frozen, classic signature of a heater that never came up to operating temperature, an internal element fracture, or harness resistance choking signal swing. Cheapest-first ladder: (1) Scan B2S2 heater current — should be 0.5-2.0A during warm-up dropping to 0.2-0.8A steady state; zero current means the heater circuit is open. (2) Measure heater resistance at the sensor connector — most narrow-band heaters read 3-15 ohms cold; open-circuit means failed heater element. (3) Check signal and ground continuity with a DMM at the ECM connector — over 5 ohms on the signal return damps voltage swing. (4) Inspect the harness near sensor 2 for heat damage — bank 2 sensor 2 on most V-configuration engines runs along the exhaust and is the first to get harness melt. (5) If everything checks out, replace the sensor ($60-$220 part). The expensive misdiagnosis is chasing phantom cat efficiency on a vehicle that just needs a $0.50 fuse for the bank 2 O2 heater that blew during a recent exhaust replacement — always confirm heater current first.

Vehicle-specific patterns: 2007-2014 Chevy Silverado/Tahoe/Suburban 5.3L L-series V8 with AFM sees P0160 from ECM-side heater driver failure on bank 2 after AFM cycles the heaters rapidly. 2004-2010 Ford F-150/Expedition 5.4L 3V throws P0160 on bank 2 sensor 2 from a blown sensor heater fuse (usually shared with another bank 2 sensor) after harness chafe. 2005-2010 Toyota Tundra/Sequoia 4.7L 2UZ-FE sees P0160 from a degraded Bosch/Denso narrow-band element at 110-150k miles, common on bank 2 first due to thermal cycling differences. 2008-2013 Audi 4.2L V8 (S5 B8, RS5, A8 4.2) throws P0160 on bank 2 sensor 2 from LSU 4.2 heater element fatigue after 100k miles. 2007-2012 BMW E70 X5 4.8i / N63 5.0i sees P0160 from harness melt where the bank 2 sensor 2 wire runs against the exhaust crossover. Estimated repair: $110 to $590.