P300 and possible exhaust leak?

[sumdude]

So i have a top swapped impala with speed daddy headers installed. Recently (well the past 4 months) I've been seeing the rpm needle bounce and the engine revving by itself when I'm in park or stopped at a stop light. I've changed plug wires... Today I got curious and took a look under the car. I'm not a exhaust expert but is this a exhaust leak? And could a exhaust leak cause what I'm experiencing?

http://s13.postimg.org/eo5prsz07/photo_1.jpg
http://s22.postimg.org/caay9mae9/photo_3.jpg
http://s22.postimg.org/d3nk28gf5/photo_4.jpg

[Twizted 1]

Looks to me like a coolant leak of some type. If it was an exhaust leak you would see traces of Black soot around the area.

[BillBoost37]

Yeah, that soot is a leak. Decent sized one as well. Whoever put those pipes together, hopefully told you it was their first time touching a car before doing that to you.

[Twizted 1]

Bill I'm not sure that's an exhaust leak.
Looks like oil deposits to me, and the pink **** that's on there looks like someone tried to silver solder it together with some of this.