I'm in the middle of changing my cat, or more like 1/4 way, the back pipe is off so the cat is still on. If I run the thing though it reeks of gas (cat still on, but its bad), is this normal or do I have another problem?

Another question, if I use a couple of nuts so that the back pipe isn't completly on allowing some of the exhaust to get out right after the cat, will that hurt anything besides people trying to sleep? Then I could ajust what it sounded like by tightening/loostening it, but everything would still be solidly held together.

 

Can't really help with the first q to much. I know my car with no cats doesn't smell like gas unless my tune is rich. I haven't ever smelled a bad cat though.

If you are just loosening the bolts between the cat and pipe to tune sound, it'll probably just sound like a huge exhaust leak. You can get a cutout for your exhaust instead, which will allow you to run bone stock quiet exhaust, or run no mufflers at all.