Code135 co2 senser sencer one bank one.

I wonder if you have replaced/identified the correct sensor. Oxygen sensors are identified by bank and sensor position. Sensor 1 is always pre catalytic converter, sensor two is always post catalytic converter. If an engine is a 4 or 6 cylinder engine the whole engine is considered bank 1, if an engine is a V6, V8, V10....., the engine bank containing cylinder number 1 (first cylinder in the firing order) is considered Bank 1, the other bank is considered Bank 2. Interpretation Oxygen sensor designation B2S1 refers to Bank 2 Sensor 1, it will be the sensor on the engine side of the catalytic converter in bank two. Check this link to determine the cylinder that contains cylinder number 1. http://www.wellsve.com/custom_searches/ds_firing.php

Most times auto parts providers offers free scans to sell parts. Just because it shows a bad O2 sensor doesn't mean that is the problem? It may be numerous things such as tune-up, mass air flow sensor, bad fuel pressure, broken vacuum lines or bad catalyst converter? Its sometimes best to take it to your local repair shop to properly diagnos this problem.