Have you had trouble finding youre down stream oxygen sensor? We had the common check engine code p0420 come up we started with replacing the upstream sensor (right behind the spark plugs) after doing this the car ran worse and a new air code came on saying the 02 heater was bad. We figured we better change the down stream sensor also and i could not find info on where it was so i made this video. After changing it nothing changed. I got a new upstream sensor and put it in the heater code went away so the first new sensor had a bad heater. At this point the error code is still there and the car is still running rough. After research the next most common reason for the code is a air leak. Im no machanic do im still trying to deside if im taking the car to a shop or if i want to try investigzting myself some more.
