I have a 2000 se with no intake or exhaust mods. Sometimes i wonder if i am just crazy, but it seems to me that occasionally after its been cold or humid, i live in austin texas and the weather has been all over the place, the exhaust seems louder. The first time I noticed it it seemed like i had lost a little power as well. the last time this happaned it stay like that for about a week then it seemde to quite down again now its back to being louder, especially as the revs increase. Any ideas what this could be ?

Thanks