my 98 ranger 2.5 , 2 wheel drive check engine light came on. something about
evaporative leak detected. i replaced gas cap thinking it would fix it.
the same code came back (CODE 455 ) what should i check next?

 

Check out the thechnical information "sticky" at the top of the page,look under "emissions" for OBD II codes and you'll find your code and a list of possible causes.