Try retightening all the clamps and screws. I had the same thing happen a couple of days ago. popped the hood and found all the clamps and what not were a little loose. i think the "pop" sound was the s&b "burping" some air. this was after almost 500 miles. took it to the dealer to have the cel reset, said everything looked fine. autozone scanned it for me the day before, got the P2000 AND P2262.