gas cap loose

[+ YOYO +]

My check engine light came on today while I was driving .. so I pulled over and checked my gas cap, it was loose but no matter how hard I tried to tighten it, it still loose. Any of you guys ever experience this problem?
Another problem is that I can feel power loss from my engine. Is it related problem?

[M34EVER]

If you pull the code it should be something like Large evap leak. Basicaly when its trying to suck the gas out it isnt getting the right suction. Most likely you stripped the threads on your gas cap and need to replace it.