have a '02 camry with 3.0l having trouble with a/f sensor codes. originally had codes p0141 and p0161, o2 sensor heater ckts. checked sensors and circuits, all test fine. replaced e.c.m. now o2 codes gone, but have a/f heater codes instead (p1135/p1155). have checked circuits and replaced a/f sensors, heater resistance was 4.5-35 ohms. now sensors ohm out correctly, have power through fuse, relay and sensors, to the e.c.m. problem is i still have a/f codes

 

Might read the post at the link below. It is for an Avalon (upscale Camry) the engine is the same.

2002 Avalon O2 Sensor P1155 Code - Toyota Tundra Forums : Tundra Solutions Forum

Toyota's can have issue with some sensors brands like Bosch. Recommend Denso or Toyota. Don't use a universal sensor.