Chassis Shuddering at low rpm idle.
 

Hello all,

I have a 2002 4eat WRX with a unifilter CAI, and GFB blow off valve. I have put about 9000 miles on my car, 6000 with the mods and there have been no problems and the engine runs strong. However, when I sit in the car after its been running and its in park every now and then the cabin shakes a bit. Not a lot, but its noticable. What causes this? Is it a problem? Also when I shut the car off it shakes a bit...almost like the engine doesn't want to stop! The car's always done this. Monday I'm having a catback, TurboXS stage 1 UTEC and Up-pipe put on the car. I also have Toyo proxes with prodrive P1s. The car accelerates and handles great! Of course I felt the need to add some more power....I look forward to the group's input. Thanks