Engine booming/resonance sound in the cabin

spak plugs themselves are fine...

I'm thinking I propably poked the down pipe of the exhaust...

booming/resonance sound in the cabin

popped out of freaking nowhere yesterday!

it's like if the car was with overdrive engaged, but it isn't, out it sounds perfectly normal, but it inside it sounds like a carburated honda accord with a folger's can type muffler, and running rich...

so...

I thought it was the muffler pipe that got crushed, because I scrape the underside of the car when I was parking it in a pretty bad spot, then I thought maybe the over drive got stuck, then I thought it could be the spark plugs, then that I was running low on tranny oil...

I verified the muffler piping, it looked round and straight, didn't check for piercing or crap like that yet...

I check the tranny oil level, was fine..

I checked the spark pulgs cables... fine

overdrive or whatever it is, operates fine (a little gas going up hill @ about 50~mph)

so, I'm basically like... wtf atm...