Lexus Error Code P1155: How to Fix It

Q: Can I drive my Lexus with P1155 error code?

You can drive short distances, but the vehicle may experience reduced fuel economy, rough idling, and increased emissions. Extended driving with this code can potentially damage the catalytic converter, so repair it promptly.

Q: How much does it cost to fix P1155 code?

DIY repair typically costs $150-300 for the air-fuel ratio sensor. Professional repair ranges from $400-600 including labor. Costs vary by model year and whether additional wiring repairs are needed.

Q: What's the difference between oxygen sensor and air-fuel ratio sensor?

Air-fuel ratio sensors are more precise than traditional oxygen sensors and provide a wider range of readings. They're used on newer vehicles for better emissions control and fuel economy, but serve a similar function in monitoring exhaust gases.

Q: Why does the P1155 code keep coming back?

Recurring P1155 codes usually indicate wiring problems, loose connections, or engine issues causing the sensor to fail prematurely. Check for exhaust leaks, damaged wiring, or oil contamination on the sensor.

Q: Which bank is Bank 2 on my Lexus?

Bank 2 is typically the passenger side (right side when facing the engine) on V6 and V8 Lexus engines. On 4-cylinder engines, there's only Bank 1. Sensor 1 is always the upstream sensor closest to the engine.

Abstract

Error code P1155 in your Lexus indicates a malfunction in the air-fuel ratio sensor heater circuit for Bank 2, Sensor 1. This sensor helps your engine maintain optimal fuel efficiency by monitoring exhaust gases, and when its heater circuit fails, it can cause poor fuel economy, rough idling, and emissions issues.