P1150
Air/Fuel Ratio Sensor Circuit Range/Performance Malfunction – Bank 2, Sensor 1
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The P1150 code is the Bank 2 counterpart to P1130. It means the air/fuel ratio sensor on Bank 2 (the cylinder bank opposite to cylinder #1), Sensor 1 (upstream of the catalytic converter) is operating outside its expected performance range. On V6 and V8 Toyota engines, this code points to issues on the passenger-side or rear bank of the engine, depending on the engine layout.
The causes and symptoms mirror P1130 almost exactly — the sensor itself may be worn out, there could be vacuum leaks on that side of the engine, or wiring damage from exhaust heat may be interrupting the signal. On some Toyota models, P1130 and P1150 often appear together, especially when cold-weather driving has damaged both sensors simultaneously.
Address this code within a week to prevent catalytic converter damage and restore proper fuel economy. If you see both P1130 and P1150 at the same time, it's wise to replace both Bank 1 and Bank 2 sensors together and have the ECM reflashed if your model is covered by a Toyota technical service bulletin for cold-weather sensor damage.
Severity
Symptoms
- •Check Engine Light illuminated
- •Decreased fuel efficiency
- •Engine feels underpowered or sluggish
- •Rough idle or slight misfires
- •Hesitation on acceleration
- •Exhaust may smell unusually strong
Likely Causes
The upstream A/F sensor on Bank 2 (the side opposite cylinder #1) has degraded or failed, reporting signals outside the expected operating range.
An unmetered air leak near the Bank 2 intake manifold or associated vacuum lines causes the actual air-fuel ratio to differ from what the ECM expects.
Heat, vibration, or corrosion can damage the wiring harness between the A/F sensor and the ECM, causing erratic readings.
A partially clogged fuel injector on the Bank 2 side or inconsistent fuel pressure can push the mixture beyond the sensor's correction capability.
Some early 2000s Toyota V6 models can set this code when driven in extreme cold. An ECM reflash addresses the root cause and prevents sensor damage.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace the Bank 2 Sensor 1 air/fuel ratio sensor
- Inspect and repair vacuum lines and intake gaskets on Bank 2
- Repair or replace damaged wiring and connectors
- Perform ECM software update on applicable models