I got this P0153 code back as soon as I replaced the O2 sensor less than a year ago. I did replace the bank 2 sensor 1. The driver's side. I erased it with the scanner and it came back on a couple days later. There's no fuel issue, no misfire, and if there is an exhaust leak I can't hear a difference. I was not able to locate any vacuum leaks. Will there be a way for me to track down the exact cause? It's got 212,000 miles on it too. Plugs, wires, PCV, filters are all on schedule.
Actually at the time I replaced the O2 sensor I also cleaned the MAF and replaced the PCV valve. It was Bank 2 which was driver's side first sensor before converter because it was saying Bank 2 sensor 1. I only have a basic code retrieval scan tool. I'm trying to figure it out myself. There is no change in performance from idle to full throttle either. It's as smooth as the day it was new. I know it's one of those LEV models so I'm sure the Check Engine Light will go on for the slightest change in sensor readings.
I asked you to confirm the sensor you replaced was before the converter since you mentioned which bank you replaced, but not which position. I just wanted to make sure you go the correct one.
According to the factory service manual, the following are the probable causes for the code.
Contaminated HO2S sensor.
Shorted /open wiring
Deteriorating HO2S sensor
Inlet air leaks.
From the other items you already mentioned you checked, it sounds like you've got the bases covered with the exception of checking the wiring. Unfortunately, real-time readings of the various sensor readings and parameters could help further troubleshoot this by checking the response of the MAF, looking at the readings from the HO2S, and looking at fuel trim numbers.