This O2 sensor is located at end of catalytic converter from exhaust pipe between the engine and firewall:
Easiest to access to have front end up in the air and crawl underneath the vehicle to reach the rear manifold, exhaust pipe and converter. The O2 sensor is just at the end of the converter.
This confuses me more because one of your other expert, Peter wrote the following:
You are dealing with bank 2 sensor 1. This sensor is located in the front exhaust manifold. Attached are a coulpe of diagrams. This is a heater malfunction in the sensor. The computer makes the ground to turn on the heater. In some cases I have seen the sensor take out the driver in the ECU. The light blue wire going to the ecu should go from 12 volts to 0 volts about 2 to 5 minutes after the engine starts. The 25 amp afr heater fuse needs to be check also. Let me know what you find. With all due respect to Greg he is not correct on the location of the sensor it is NOT in the back exhaust manifold by the firewall that is bank 1, bank 2 is the front exhaust manifold. That is where the senor is for the code p1155.
Read more: http://www.justanswer.com/questions/12xkb-i-have-a-toyota-sienna-2002-have-a-code-p1155-i-will-like#ixzz0rVcdng00
Now which do I follow and am not sure which one of you is the correct answer!
Bank 1 is always the side that cylinder #1 one is located. In this case the #1 cylinder is located on back side of engine:
Although the below is for Lexus(made by toyota) it applies to all vehicles with a v6 or v8 engine:
Manufacturer specific codes:
See also: Toyota Check Engine Light (at www.Check-Engine-Light.com)
another toyota specific obd2 chart:
Welcome to the Toyota Check Engine Light codes page. Below you will find the most complete list of Toyota trouble codes available. The code definitions are a good starting point when determining the cause of the service engine light but where do you go from there? We have a large number of resources to help you repair the problem.
We do our best to update these Toyota check engine light codes as frequently as possible. If you find one missing let us know and we we'll add it immediately! Please use the form on our Contact Page to get in touch with us. We certainly understand how frustrating it can be to look for a code definition and have it not online when you need it. And lets face it, if the service engine light is on then you need it now! It's easiest to use the "Find On This Page" feature of your browser's "Edit" menu to find codes on this page as the list is quite long. These are listed in numerical order for easy searching.
When retrieving Toyota check engine light codes with an OBD II scan tool, proceed as follows:1. Connect scan tool to the 16-pin data link connector (DLC) located underneath the steering column. The connector may have a removable cover.2. Turn the ignition on.3. Follow scan tool manufacturer's operating instructions to access the Diagnostic Trouble Codes (DTC's).
Remember, these are manufacturer specific codes only. Refer to our Generic OBD II code list for definitions on all other Toyota diagnostic trouble codes.
Below shows why we have to look for the manufacturer specific code if available, as you can see it refers to many different things for the different manufacturers:
This is what autozone says:
(refers to Bank 2 Sensor 1) for Toyota Sienna 2002. I am confused as to which one to beleive. Looks like I'll have to check each sensor separtely before I replace any!
A/F Sensor-21 (Bank 2 Sensor 1) Heater Circuit Malfunction
A/F sensor heater circuit or ground circuit is open A/F sensor heater power circuit is open A/F sensor heater is damaged or has failed PCM has failed
Autozone uses the generic obd2 codes, which are not the same as manufacturer specific trouble codes definitions.
The listing I have given you from several sources are all Toyota Specific trouble codes, but I would advise to call your local toyota dealer to confirm
The whole information was wrong. It was the Bank 2 Sensor 2.
Bank 1 sensor 2 should show the OBD code of 1135 and NOT 1155!
All the above mentioned brand specific codes were wrong!