running rich of passenger side

[lowrodderchev]

got her (2001 5.3) fired up after running a few minutes she started to run rough black smoke out the right side. well a buddy of mine pointed out my MAF sensor was backwards so I flipped it around pulled the passenger side plugs and they were all covered in black soot. cleaned them off and fired it back up ran fine for a few minutes then same problem again. I have brand new o2 sensors (front only I have no smog so no cats) so Im pulled the 02sensors cleaned them up (didn't look bad) and I'm putting new spark plugs on the passenger side(drivers side looked fine) if it doesn't work any suggestions? thanx