(Kinda') Rough Idle
 

Had this truck a couple months. Replaced: plugs; wires; distributor cap & rotor.

At idle, when warm, she shakes/misfires occasionally - seems to be getting worse lately. Runs OK - exhaust is kind of loud (has a small pipe after muffler) and I'm wondering if there's a leak as she pops on decel.

Pulled codes:
KOEO:11
CM: 33
KOER: 41; 33

So - code 33 is an EGR issue (not opening) and 41 is a lean running/O2 sensor issue but would either of these produce the symptoms I have?