Lincoln Town Car 1996

I have a 1996 Town Car with 178000 miles. Sometimes, after I have been on the highway for an hour or more, and I get off the highway, and stuck in slow moving traffic I can smell gas fumes. I can smell them under the hood, but I cant see any gas leak marks or fluid gas leaks. Could it be the fuel injector(s) need to be replaced?

I have read some of the other posts and I am going to check the carbon cannister and hoses. But if it was leaking injectors how would I check for that.