Some Problems With 02 Sensors

[TeXJ]

Great site you all have here. Glad that I found it. I have a 97 es300, with about 100k miles on it. I have received the codes p0125 and p0155. P0155 is saying bank2 sensor 1, so I replaced the o2 sensor behind the cat. Then I cleared the codes with my code reader. After about a few minutes of driving the check engine light came back on and was reading a p0125 code. So then I drove some more and sure enough, the code p0155 popped back up. I'm lost at what this could be. I searched on this site and google and I couldn't find anything to do with p0155. The code p0125 seems to be a code that is tripped due to the impending malfunction of a o2 sensor.

any help would be appreciated.

thanks

[gordonw]

You replaced the wrong sensor. Bank 2 Sensor 1 is in front of the engine. Its in the front engine manifold.