sorry for another thread on noises

[sarswimmer22]

Hello all. Sorry for another thread on noises but I am having a big issue and need your guys help. I will try and make this short and simple.

I own a 2011 2SS/RS with only 7681 miles. Only mods are K&N CAI and did a muffler delete a week ago. With the muffler delete they added a Magna-Flow Stainless X-pipe. After driving the car and loving how it sounds soon after I noticed a growning sound coming and going when im on and off the gass! Its coming from under the car along with a slight vibration. . I was wondering if its my AFM??? Maybe the muffler delete caused it to be more noticeable.

Also, my car has not started twice on seprate occasions. drove it the store yesterday..no issues...came out of the store and it wouldnt start! Tried again and started right up. I have no warning lights or indactor lights..nothing to tell me anything is wrong.This all started AFTER my muffler delete. Please help guys! Thanks for yor time!