I have a 2007 honda civic si. When i first got it it had a deep throaty sound to the motor when i floored it and the vtec would kick in. Now i can barely hear when the vtec hits, it just sounds loud the whole time. my cousin has the same civic with about 30,000 less miles on it and his sounds alot better. i have 55,000 miles on my car. does anyone know why this is happening?