Question no.1: there is a slight exhaust noise, but i can't tell what is causing that. if i decide to replace the muffler, can i do away with the resonator?

question no. 2: i previously asked a question about EGR code detected. one technician replied asking what the code was. i did not reply because i cleared the code and i have to wait for next time it shows up. i was reluctant to go ahead and replace the egr valve, and my thinking was well-founded and i later discovered from another website that the culprit for the egr code was 99% of the time the VSV(?), it's an electric part that't connected to the egr valve. i don't have a vacuum pump or an ohmmeter to do some testing. i was thinking to replace the electric part, it 's located near the passenger's side wheel well in a hard to reach place .