Ok guys....as per wolfsburg's suggestion and similar symptoms I went with what my gut instinct was telling me. The Cat was totally clogged and the EGR was stuck open releasing all of the cars exhaust back into the intake. I removed the EGR temporarily to let it breathe and took the car down the street to my local shop. He bored out the Cat and blocked the EGR. Hour and a half labor, $100 cash and now the car starts and runs better than ever! I though my 300 was supposed to be slow and stately, the thing really moves now! Crisp throttle response, great acceleration and feel. Like it was 1987 all over again.
Thanks again for the constructive help, I had a feeling all along it was the cat after reading wolfsburg's post. I think everyone should have theirs removed to avoid future troubles...cheers! :dancefool:

Took her on a highway jaunt yesterday, got up to 100 in a big hurry no problem, no excess smoke. The car wouldn't do over 60 before. Soooooo happy!:)

Good job!

Now, that's way better than selling it..........right?!!

Now you need to fix the EGR, permanently.

done, installed a block plate so no more soot or exhaust can get in there.