All the shltt yall telling him isnt going to help!!!! everything yall are telling him is going to raise the NOX levels way beyond what it is now!!!! Listen to what I have been telling you!!!! O2 sensor will not affect the NOX levels!!!! Only HC CO...Oil change will not even come close to dropping a .1 point in anything!! yall all are NOOBS when its coming to this so stop telling him stupid an wrong shltt!!!