Just recently my riviera's service light came on, I took it to auto-zone and they ran a diagnostic and said it was multiple cylinder misfire, the guy just recommended getting my car serviced. I went to a mechanic and had my oil changed, ran fuel cleaner through it, and got my PCV valve changed, which was shot, this was 2-3 weeks ago, now I'm hearing a weird windup sound coming from my supercharger, and it still feels like I have a lack of horsepower, what could be that causes of multiple cylinder misfire and how do I fix it? Along with the sound coming from the supercharger.
