2003 Chevy Tracker LT 6 cyl. Emissions Problem

What is your question?

I have a couple issues that I know of...1) my check engine light is always on and I had to replace my original gas cap because it broke (it had a spring inside the original cap)...however, light never goes off. Also, when I drive I can usually smell fuel/gas, which according to diagnostics appears to be an emissions control issue...? I don't even drive on the thruway anymore because it just cannot keep up with other traffic. Going around certain curves or small hills it seems to "jump" lanes if I am going around city speed limit of 30. I have had a full tune up as well and it didn't help much. Tina W. The Tracker has approximately 104,000 miles on it.

What makes this problem better or worse?

After driving for a few minutes

How long has your 2003 Chevrolet Tracker had this problem?

several months