It's been on for a while but I just put it in N and revved it a lil at a stop light and it started flashing for about 15 seconds then went back to being steady lit? What does that mean?

 

If it's working right it flashes during a serious misfire. If the cel is on you must have a code. If you told us that code we could probably be more helpful.

 

A flashing check engine light indicates a serious misfire, which if ignored, will absolutely destroy your catalytic converter.

Are there symptoms??

Post the code here for comment and resolve this ASAP.

As a general rule of thumb, never ignore a check engine light. Your Jeep is trying to tell you something and you're not listening.....