Oil smell on startup

[Syrma]

Any idea's, I have a really strong smell of oil on startup, it's fine when warmed up, except when driven hard. Also, the exhaust has suddenly got a lot louder, any idea's?

[Brealbags]

first thoughts would be check oil level - overfilled oil burns off which would smell, especially when cold where the oil is thicker. This also could damage the cat which could explain the car been louder.
have an emissions check and look at condition of spark plugs for an indication of engine health.

there the first things id do anyway there could be other reasons hope this helps

[Syrma]

BTW car is decat'ed

[Brealbags]

baffles in exhaust could have collapsed then or summat