Can a really bad muffler cause a loss of power?And can it cause a code reading for the EGR System?

Can a really bad muffler cause a loss of power?And can it cause a code reading for the EGR System?
A clogged exhaust system will cause loss of power, but if the muffler is only rusted and leaking.
Only if the EGR portion of the exhaust is clogged will a code for EGR be set.
What code are you getting, if any?

Capt.Rich: I get a code of 332 insufficient EGR flow detected. I had the EGR valve checked and it holds vacuum.I replaced the actuator but I still get the code.