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.


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.


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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