my car wont rev past 3000 when I press on gas it makes a loud noise and an high pitch whistle noise wont go past 20mph. I have the code p1320 currently. the day I lost power I took it to autozone and got two codes p1320 which I had for months and p0420 which went away a few days later. you think I need a new cat maybe its clogged I did have a misfire a a few months back