The light showing showing emission sensor malfunction came on. I checked the code. It showed P0460 (bank #1). I do not notice anything wrong in the motor performance, except sometime during acceleration I can smell gasoline. what should I check first to diagnose exact point of the problem?

 

P0460 is for the fuel level sender. You'll probably need a new sender/fuel pump. I'm pretty certain it's unrelated to the fuel smell, though. Find that fuel leak. Not good mojo in a hot engine compartment.

 

I've had the top of the fuel pump of both my civics crack which caused the inside of the car to smell like gas. I did not have that code.