slew of codes, help!

i still have 2 02 sensors left from when i put the headers on, so maybe i can switch them in and give it a try? or should i just bite the bullet and get vette 02's? there is also a small leak at the driver side collector, i read that could cause a problem if the leak is 6-12 in. from the 02. thanks guys! the vette 02's won't help
what kind of sound? how bad of a leak is it
i'll pull some plugs tomorrow, it just seems weird that the code is for both sides but the noise is on one.

