No offense Scott but the weld in your first post looks like poop, that certainly couldn't have helped the problem.

The weld in the second pic looks much, much better.

I'm running a flex pipe right at the end of my dp.

 

the first (really the second) turned out to be nickel weld....because the "professional" welder i took it to decided that the manifold was cast iron. The second weld was TIG IIRC.

But regardless of how well it was welded...you cant weld a stress point, continue to heat and stress it and think it's going to hold again for the 3rd time

i doubt it would have failed to begin with if I hadn't bolted the downpipe up. It also came cracked, after I put that kit together (bought second hand without an ounce of knowledge) I took it straight to a dyno. While it made 170rwhp with just a FMU/bipes and 6psi, it also was apparent the construction was **** and there was a reason he sold it.

 

x2 lol