Hi, I am new to the club and I am sure this topic has come up before. I just bought a 2000 X 3.3 (XE) and the other day I had the ses light come on, I ran the code reader got these two codes 325 (knock sensor) and 128 (O2 sensor). When we ran the codes we noticed that the car was runing rich would this mean that the knock sensor is bad since it setting off the O2 sensor? Now I am not sure what to do since I have read in previous posts that the knock sensor does not need to be replaced on these engines? I thought since the truck was sitting for a few months I thought it might have been the gas, I used lucas fuel treatment but the codes came back after a week. We just cleared the codes but the truck seems to idle a little rough? Would a bad O2 sensor make it run rich? Can I switch the rear sensors to see if I get a bank one code rather than bank 2 to rule out a bad sensor? Any suggestions would be greately appreciated.