I have an 03 sixer and I have been havin a problem recently that bothers the crap out of me to say the least. When im running in higher RPM's in 3-5 gears my car stutters and makes a really high pitch wining sound. I have no clue what it could possibly be but it is robbing me of already LOW h/p! has anyone had a problem like this before? i already changed spark plugs and fuel filter. Anyone know what might be goin on?