Clarification: By "gas" do you mean fuel?

Nothing is going to be fixed by aimlessly tinkering with the plumbing of the lines. Put them back the way the SHOULD be, and start looking for reasons why there is a smell eg, cracked hoses, leaky fuel filter.

Try steam cleaning under the hood and when dry, use a decent splash of talcum powder around all the fuel lines to check for moisture (powder up, idle the car for a few minutes, and look for where the powder sticks).

Now if by "gas" you mean a rotten egg sort of smell that is usually a catalytic converter that needs changing.