blacksunshine04

Haven't been here for a while, and I searched for similar posts before I decided to make this one, and found stuff close, but not quite cigar worthy.
Ok. I have an '04 Grand Cherokee 4.7 HO, and it burns oil, but not all the time. It mainly happens, like 99% of the time, while sitting at idle for medium to long periods of time.
I can smell the smell of oil burning, and see a little blue smoke. If I rev the engine a little, or when I finally take off, a considerable plume of blue smoke emits from my tailpipe.
After that, no more burning oil smell, and no more smoke. It doesn't blow smoke out whilst accelerating, or while decelerating, just if I idle for some time. I have an engine light, and the code is for the cats. I had them scoped a while back, and one bank is on its way to being clogged, and needing changed. I changed my pcv valve a couple thousand (if that) miles ago, and it changed nothing.
This doesn't occur every time I'm at idle for extended periods of time either, rather somewhat intermitently. Not sure if this could be bad a bad ring(s) or maybe bad valve seals. I know the pcv change did nothing, so there goes the cheap fix.
It would be nice if someone with more knowledge than me, or someone who has had this same problem (and fixed it) could give me some insight on what I may be looking at.
Thanks.

Noah911

That blue smoke is a tell-tail sign right. But, what would possibly be causing this, and is the reason(s) for it burning oil? Losing oil? Would you be at all worried about it being a head gasket? I don't know why, but it doesn't sound like it would be that to me?

Blue exhaust smoke only at start-up can indicate worn piston seals or damaged or worn valve guides which may also cause a rattling noise.

Other:
Possible causes of blue exhaust smoke include: piston wear, worn valve seals, a dirty or non-functioning PCV valve, worn piston rings, an intake manifold gasket leak, worn engine oil seals, and possibly even head gasket failure.

I wonder how to test and find out each of those possibilities?