So this is my third c5 vette (1 coupe 2 z06's) and the first two I have had both had lg pros on and never had a problem with them. They made great power, great fitment and no leaks. So my problem is with my latest z06 and it came with a set of lg pros on it as well. I kept hearing this exhaust leak and have been searching for awhile trying to track it down. I thought I had it narrowed down to the air tubes leaking because it looks like the previous owner of the car tried to have one repaired because it has some big fat mig welds on it that I know lg didnt do. That is on the driver side and it still is leaking but not that bad but still none the less it leaks. The passenger side was genious lol. Whoever installed them decided it would be a great idea to put a piece of rubber ss braided hose to connect the air tube and well exhaust heat + rubber hose= huge leak after melting. Any ways today I was under the car just bored really looking around at things and I finally found where the leak was and the pics will show.. Here is the thing do you guys think the welding on this driver side header is just defective or what? I mean the air tube leaks at the connection on the header not the connection to the air tube itself and then right here where the mounting tab is connected to the header. The passenger side header is fine with no leaks so it makes me wonder.. Anywho here are some pics of what I had happen, any comments are welcome..

 

I wonder if that pipe being hit broke the weld. With the groove in that pipe it hit something. I would have it cleaned and welded.
I don't use the bell housing bolts. IMHO they are a high stress area.

 

I've read that LG doesn't recommend you use them either just for that reason.

 

Exhaust components expand and contract with heating cycles and it doesn't look like the bell housing bolted connection has much give. You took very good pictures, you can see the stress cracks in the header tubes starting at the weld and moving out. It may have started with the header tube hitting something but now with heat and vibration, the cracks will keep getting bigger.

 

Well both have been hit on the bottom as well and odd that you guys say that because the other side the bolt is missing and of course no cracks.. Guess I am going to bring it by a local muffler shop and have them try and weld it up..

 

Well both have been hit on the bottom as well and odd that you guys say that because the other side the bolt is missing and of course no cracks.. Guess I am going to bring it by a local muffler shop and have them try and weld it up..