Need help...fuel tank pressure sensor circuit low

My check engine light came on recently so I pulled the code... "P0452"

I looked it up online and it says something about a fuel tank pressure sensor circuit low. The general coding tells me it's something to do with the evaporation system, but I would like to get this fixed! Can someone point me in the right direction? Might I have a leak, etc.?

Thanks

P.S. I had a forged longblock put in and am running about 10.5-11 compression I have been driving it a couple months now before this light came on.