P1153 — HO2S Insufficient Switching (Bank 2 Sensor 1)
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1153 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1153 means on specific makes
Heads up: P1153 is a manufacturer-specific code, so the same number means different things by make.
Chevy / GMC / Cadillac / Buick CAUTION
Identical to P1133 but on bank 2's front O2 sensor — not switching fast enough. Same lazy-sensor / lean / exhaust-leak family of causes.
- Lazy upstream O2 sensor bank 2 ($50-150)
- Exhaust leak before sensor ($50-200)
- Vacuum leak ($0-200)
- Contaminated sensor ($50-150)
Check first: Scope the bank 2 front O2 waveform; check for exhaust/vacuum leaks affecting that bank.
Source: engine-codes.com P1153 GMC / KBB
Subaru CAUTION
The front oxygen/A-F sensor circuit on Bank 1 is out of expected range/performance. Source descriptions vary slightly (range/performance high). Common with P1152 and lean/rich complaints on Subarus.
- Failing front O2/A-F sensor ($100-250)
- Blown O2 heater fuse
- Poor sensor connector contact
- Wiring damage to ECU
Check first: Inspect the front O2 sensor, its heater fuse, and connector; replace the sensor if signal is out of range. Often paired with P1152.
Source: engine-codes.com/p1153_subaru.html, justanswer.com Subaru P1152/P1153