I have a 2002 Camry V6 with 149,000 miles. My check engine light is on. The code is P1135 Bank1 Sensor1. I purchased an Upstream O2 sensor (Bosch) from AutoZone and changed the front one (right behind the fan) and reset the code. The check engine light went off for a brief moment. But, after a few second the light came back on. I went back to AutoZone, and the sales person told me that often both sensors go bad and suggested I change the rear Upstream O2 sensor as well, which cost another $130. I wanted to see if that's truly the problem and should I go ahead and change it. Please help. Thanks.
You may need to have your computer "un-learn" the old O2 sensor. Unplug the battery for about 30 minutes. This will reset your computer back to factory, where it will then have to relearn the new O2 sensor and might alleviate the situation. You will probably not know for several warm-up cycles if this actual solves the issue for you.
Also, did you double check to ensure you received the correct O2 sensor? Another thought is that the new O2 sensor might be bad. It would not be the first time this has happened. Here is what the code for P1135 is telling you (from Engine-Codes.com):