I have a 97 Avalon and the check engine light is on. I have reset it numerous times. I got a code reader. It shows a code PO135, 02 sensor heater circuit malfunction, bank 1, sensor 1. Should I replace the O2 sensor? If so which one is bank 1 sensor 1?
Thank you for your help, Robin
From the Toyota M/M: Bank 1 is the bank that includes cylinder 1 (Front Bank) Sensor 1 is the sensor closer to the engine body.
Maintenance book says to check the resistance of the heated O2 sensor heater(S/b 11-16ohms)?
Book also mentions checking the ECM . HTH
Yeah, 99.999% chance that the sensor is to blame. Bank 1 is the cylinder bank in the REAR, not the front, and you can verify this by following the intake runners. The first intake runner will go to cylinder #1, which is in bank 1. Before you go trying to get that sensor out, I would recommend spraying it with some sort or rust-penetrant or the like to minimise the chances of it seizing in the exhaust manifold threads. Or, have someone else so it! :) Just make sore they replace the correct one.
Just had that problem and replaced the wrong one. It seems that the rear one is the one that always go out. Probably because its the hardest one to get to. The factory original requires no wiring but is more costly...
Peace Da Ghost
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