Spintec mufffler install

i recently installed my spintec 9000 muffler on my truck and it feels like it lost a lot of power. I checked the exhaust and where the connections or for the new muffler and there's a pretty bad leak from both sides of the muffler and there's a lot of black liquid from those areas. Is that the reason for my loss of power? I can hear the leak and when I put my hand there i can really feel it blowing on both sides. The first pic that big black mark is just tape from when I bought the pipe any input would help

 

I don't know but the loss of power could be that there is a leak and it's not all going through the whole exhaust system. I know it's pretty exhausting trying to find the answers( haha I had to) but hopefully someone will know.

 

Your gonna lose low end torque with a loss of back pressure from the exhaust leak. It would have to be a substantial leak for you to feel a loss of power.

 

I don't see a muffler in those pictures

 

It's right above the muffler

 

The truck ran great until I installed the muffler and found the leak.