Code P0155

Hello guys, everytime I have an opportunity to listen to your show, I do your guys are a riot and I like it!

Here goes the question… I have a 2002 Tundra, with about 96K miles about a month ago the engine line came on, I went ahead and check it out and it is a P0155 code, which is a Bank 2 Sensor 1 heated code, went ahead and replaced the $en$or; reset the ECM, drove the truck, then about ten minutes into the drive the light came on again; checked the code and it is the same code. I thought replacing the sensor would correct this problem, but it does not want to go away. Is there anything else I can look into without having to replace the ECM? Should buy another vehicle?

Have you check for correct voltage leves at each pin?

No I have not checked the voltage at the pins? Are these the pins at the connector of the Sensor or the ECM?

Those codes don’t necessarily indicate a problem with the sensor. They only tell you that there is a problem in the sensor’s circuit. I’d say that you took the expensive diagnostic route - now that you replaced the sensor, you can be pretty sure that the problem isn’t there. So you’ll likely find it in the wiring to the sensor.

Check this out:

You would like to fix the oxygen sensor heater problem by changing a part. It would take some troubleshooting of the O2 sensor heater circuit to determine what to do. It could be something as simple as a broken wire; but, you can’t find it (except by blind luck) without the use of an electrical multimeter and the wiring diagram to identify the particular circuit.
Here is the wiring diagrams (for 6 cylinder engines, and 8 cylinder engines) which includes the oxygen sensor heater circuits: Click on "Engine Controls (xxx-xx)(2002).

Hello Backyard Mechs, I bought a new HO2 Sensor 1 for bank 2 and that was a quick fix, it took me longer to get under my truck than to R&R the sensor. I guess the dealer did not want me to replace the right Sensor as they gave me the run around, costing me an extra $100 dollars (thanks to the dealer), but thanks to you guys the right sensor has been replaced and the truck is running as good as new…

Are you saying you replaced the wrong sensor at first or you had a defective part at first? Both of your posts read Sensor 1 Bank 2. What do you mean about the Dealer not wanting youto replace the right sensor and a run around?

Oh, you mean expressing oneself intelligibly is a requirement?

The dealer’s parts department person did you a favor by insisting you use the correct type oxygen sensor. You truck requires a Wide Band Oxygen Sensor in the front of the catalytic converter. The cheapest wide band oxygen sensor, for your truck, at Auto Zone, is $179.[]
You were lucky, this time, that it was a faulty wide band oxygen sensor. One is not always so lucky that one can throw parts at a problem and the first part thrown works successfully. This, of course, sets up the belief that it will always work. (Hint, it won’t).