Hello atikovi. I do have a code P0420 which could mean the sensor could be bad or that the converter is bad. When I bought the car, the center cylinder had a nonfiring coil. I can only imagine the extra fuel hitting that converter and the two sensors. According to abcared00 in a previous post, the sensors I have could be lazy and not reporting proper values to the computer. If the new sensor doesn't help, and a new primary sensor don't help either, I'll change the exhaust out. The exhaust system is the only error code I am seeing. Reading back in other posts, one owner found the converter broke up inside when the converter was pulled. If this error code will stay clear, that will be a good step forward to resolving my herky jerky. ALL parts of the system will have to be checked and cleared till the culprit is found.