Corvette has been running hard lately. Smelled gas a while back and check engine light came on. Since then, about 30 min into a drive it will throw the engine light again, but turns off after it rests. Just the other day it decides to quit at idle after a 30 or so mile drive. Replaced MAF sensor and still have the same issues, only this time the fuel smell is much heavier. So I'm at vacuum leak troubleshooting. It's got a pretty loud hiss and its had that for a while now, I'm expecting as of now that it's not a good sign. Sounds like it comes from around the throttle body or at least the air intake. It's got a K&N filter and a BBK power plus throttle body. I'm unaware of any other modifications. I removed the MAF and made a seal around my mouth and blew into the throttle body via the rubber hose deal. I get a small hiss and it pressurizes to a point until I pull away and some of the air comes out. I'm at a loss for what to do from this point forward. Thanks in advance for any advice.

Edit: I removed the MAF sensor plugin and it will run fine on its own after startup. But it causes a backfire when giving throttle.

 

First thing is to see what the code is. Next thing is to get a scanner and you might be able to see data