Am I running rich?

[519]

I've noticed lately that if I'm driving in a garage or any closed space and stick out my head through the window, I smell a strong scent of gasoline. I've read somewhere that this is a symptom of the car running rich. Would a dirty air filter cause that problem? Since mine is due for a change soon.
I'm just wondering if I should worry about the smell

[toyomoho]

Check the exhaust for this smell. A rich mixture is hard on the catalytic converter. If this is the problem, best to fix it ASAP. Check the fuel system for leaks, gas tank venting system, gas cap, emissions systems plumping and charcoal canister. The last item may be under the car in front of the gas tank.

[Doctor J]

Rich mixture usually manifests itself by strong rotten egg odor and loud backfire upon abrupt deceleration. Smell of raw gas usually means there is a vapor leak on the fuel system or a small liquid leak after the fuel pump. Make sure that the gasket on the gas tank filler cap is not cracked.