CONDITION: A vehicle owner living in Portland, Oregon performs a DIY maintenance on his 4 cylinder Camry, including spark plugs and universal oxygen sensors. After the repair the check engine light was illuminated. The vehicle was then driven to a professional repair facility. The service technician defined the check engine light as a Diagnostic Trouble Code (DTC) P0135 (O2 sensor heater circuit bank 1 sensor 1) with his scan tool.
CAUSE: Repair shop is located in Portland, Oregon; however this particular Camry is equipped with California emissions. An oxygen sensor, designed for non-California emissions vehicles was installed rather than the required air fuel ratio sensor.
CORRECTION: The recently installed oxygen sensor was removed and the proper air fuel ratio sensor was installed on the vehicle. The repair switched off the check engine light.

NOTE: All DENSO air fuel ratio sensors use a 9 in the fourth digit of the part number (i.e. 234-9xxx).

*May also be seen in various models which have similar system configurations (e.g. California vs. non-California models; Ultra Low Emissions Vehicle/ULEV vs. standard models).


Product Group Assembly Category
Emissions Oxygen Sensors Repair Procedures
Year Make Model
2001* Toyota Camry*

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Published on: July 18, 2022

Filled Under: Technical Articles

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