P0150

P0150 is the bank 2 mirror of P0130 — the upstream sensor on bank 2 (B2S1) is producing an implausible signal or no signal at all. V6/V8 and flat-engine only; doesn't apply to inline-4s. CRITICAL: get the FSM bank diagram before you touch anything. On transverse V6/V8 platforms (Toyota 2GR-FE, Honda J35, Chrysler 3.6L Pentastar, Ford 3.5L Cyclone), bank 1 is typically the REAR bank closest to the firewall and bank 2 is the front bank; on longitudinal applications (most pickup trucks, BMW, Mercedes RWD) bank 1 is the right/passenger side. Replacing the wrong sensor is the #1 mistake on bank-2 codes. Same diagnostic ladder as P0130: connector inspection for corrosion/oil contamination, signal-wire scope test for switching (0.1-0.9V narrow-band at 8+ cross-counts per 10s, or 1.5-4.5V steady on wideband AFR), heater resistance check (6-15Ω narrow-band cold).

Vehicle-specific patterns: 2007-2014 Toyota Camry V6 / Avalon / RX350 with the 2GR-FE — bank 2 is the FRONT (radiator side), and the front upstream sensor is the easy one to reach but the one customers often replace by mistake when bank 1 (rear, behind the intake) is the actual problem. 2005-2012 Honda Pilot / Odyssey / Ridgeline J35 — bank 2 is front; throws P0150 when the front exhaust manifold gasket fails. 2009-2017 Chrysler 300 / Charger / Challenger 5.7L Hemi — longitudinal, bank 2 is driver side; throws P0150 from the same TIPM issues that hit P0135. 2011-2019 Ford F-150 3.5L EcoBoost — longitudinal, bank 2 is passenger side; P0150 often appears after a turbo-side coolant leak migrates onto the sensor. Cost band: $200-$500 for sensor + labor; access on rear-bank V6 transverse platforms can push labor up 1-2 hours.