I changed my oil a week ago, drove my car around for about 30 minutes and let the new oil curculate. It sounded normal. I parked my car in the garage and didnt drive it for 3 or 4 days. When I crunk up my car it sounded a lot deeper. The exhaust was louder as well as my intake noise. I figured it was the humidity. the next day it was cooler and the humidity was low so I took it for a spin again. Still, it sounded deep; a lot deeper than before. I checked my oil level and it was fine. My VTEC worked great still but was very very loud (much louder than normal). Any cause for this? Should I check my plugs? I dont feel a power diff. so i dont know.

 

Did you use an RSX Oil Filter?

 

Maybe your old oil was really shot to hell and now the car has new blood flowing?...

 

Do you have an aftermarket exhaust/header? Check your exhaust system.

 

Check airbox lid?

"Crunk up" hehe.