I have an UR turboback exhaust that has been properely tuned and installed. I get 2 P0137 codes (02 sensor low voltage) that come up regularly. I turn them off using an OBDII code scanner but im getting really sick and tired of these codes. I wanted to know if anyone else is getting these same codes. The car has been tuned by Sean Ivey so I know that the tune is not the problem. The test pipe i have has a mechanical fix so i just dont understand what could be going wrong. Any help would be highly appreciated. Thanks.