Recently installed my XS headers now I have a vacuum leak, I think.

First of all could it be something else, maybe a crack in the header. I know that cracking in these headers is not a rare occurence, but I just installed these last weekend. The noise is coming from the rear of the engine so is there a common spot for leaks or is there somewhere I should look in particular?

Check engine light is killing me, but added power is fun

 

first exhaust leaks are NOT vacuum leaks

anyways look at the vacuum line that comes off the back of the manifold (next to the brake booster hose), and goes to the firewall (it's for the mounts btw)
very easy to knock off that one, especially when working on the back of the engine

 

I know that they are two different leaks, but I don't have a OBD II tool to actually read the code and the shop I went to today said it would be $80 just to read it. and I have no real experience with any situation like this because this is the first car that I have ever done anything like this on, so I know what a vacuum leak would sound like because that is easy to replicate just by unplugging one of the lines but what would a exhaust leak sound like, would there be a smell? I would assume so.

On that note I will have plenty of time to figure it out because my car is now out of commission for a bit FML

 

more of a pulsing sound, due to each cylinder firing seperate
smell, some but not really though


try taking a long piece of tubing (coolant line works), put your ear to one end, then the other end to the exhause flanges/gaskets are, and kinda listen, and then move along it to listen to the whole thing, it should stand out preety well