i drive a 1992 honda civic cx hatchback with 160 000 km and i have a fuel leak coming from the gas tank. when i loosen the gas cap it stops leaking because theres no presure. by driving with no gas cap or a loose gas cap is it causing harm to my engine or car? and if it is what can it do to my car?

 

Either way is unsafe, get it checked out and fixed. Driving without a gas cap... any source that could start a spark can light your car on fire. Driving with a leak... you contaminate the streets and put yourself and others in danger since it leaves a line of gas tracing back to your car... thus same thing, any spark = fire.