Hello guys. I have downstream oxygen sersor problem changed the sensor deleted all codes (p0136 p0137 p0138 p0139) and removed check light. After driving 50miles check light come back and now it showing p0136 and p0137 codes but the oxygen sensor is brand new. What can be problem? There is something i cant see?
I see the issues what can cause this codes but exhaust system not have leak and also wires are in good condition
What voltage do you see on your scantool for the downstream oxygen sensor? Check at different conditions while the engine is running. What brand of sensor was installed? I only use a Toyota or Denso from a reputable source. Posted via the PriusChat mobile app.
Is the cat aftermarket or oem? I had this problem shortly after installing a cheap aftermarket cat on ebay
Its just taiwan brand i dont know its voltage I have ford fusion hybrid cat and its so good i checked one day ago