Interesting. I looked at the manifold some and noticed more cracks on either side of the O2 sensor. I did pick up the new manifold today, its in good shape, just one broken stud on the down pipe I gotta get out. If this one cracks I'll have to look into a header like the other poster suggested. I can't to hear what this sounds like with no leak, I believe it's been leaking since before my Father in law bought it