One problem related to engine noise has been reported for the 2007 Toyota Prius. The most recently reported issues are listed below.
I experienced a scary situation with my 2007 Prius today. While I was driving all of a sudden the abs brake light and dsc light and (!) light and brake light came on and stayed on. The car also made a loud buzzing noise in the cabin. I pumped the brakes and it was not very responsive. Luckily nobody was around because I felt had I needed to stop on a dime, I probably wouldn't be able to. I looked around online to find if others have had this problem and it appears there are plenty of cases where this type of sudden failure has occurred under 2007 abs Toyota Prius brake module complaints. I believe that there is a recall for this issue from the manufacturer. Please contact me - I need help!.