I have a 97 Lexus ES300 and the check engine light and track off light WONT GO OFF
i went and got it scanned and it was my o2 sensor (code P0135) went and got it replaced (bank 1 sensor 1) also the day before got another sensor put in I believe it was bank 2 sensor 1, the mechanic had to go under the drivers set to put it in.
but long story short both lights keep coming up after 10-15km after being cleared by scanner
the only code that's coming up is the one "P0135"
WHAT ELSE COULD BE THE ISSUE ??? Is there a fuse for the oxygen sensor or could be a connection gone wrong somewhere ANY IDEAS WHAT COULD IT BE ???

 

It could be a short

 

^ What he said. If it's not the bank 1 sensor 1 it's likely the wiring from the connector. FYI the sensor under the driver's seat is the Bank 1 sensor 2 (downstream) O2 sensor.