leaky valve covers cause smoke scene?

[Makdaddymac]

im looking for what i htought was myy aod leaking again, and it seems i just have a lil coming from the dipstick tube, (the tranny is over full).. but i noticed oil over the place in the upper back. even some on the o2 sensors. i thought my rear main seal was causing it, but i think my vavle covers are leaking worse. maybe the seal and valve cover seals are tag teaming.
i just wanted to know if a bad valve cover leak would burn off the rear cat on the h-pipe or is that to far??

 

[black5.0lx]

I just finished getting my car back together this weekend. Did a HCI swap and you wouldn't believe how loose the valve cover bolts were. Also the intake was leaking like crazy at the back of the engine. So what I thought was a rear main seal or even oil pan was all coming from the top side of the engine. I sprayed brake cleaner all over the bottom end while I was working it and I've ran it for two days now and haven't had a drop on the driveway. Tom