A gasoline leak or fuel leak is an absolute cause for a vehicle to fail the smog check. A smog check repair station needs to find the location of the leak and fix the problem. This is a huge safety concern, much greater than passing the smog inspection.
We recommend following the link below to learn about California's CAP (Consumer Assistance Program) which will pay up to $500.00 toward your vehicle's smog check repairs at a CAP certified smog repair station. If after the state spends $500.00 to repair your vehicle, your vehicle needs more repairs and you are unable to pay for it due to economic hardship, a smog check referee station may award you a one time 2 year smog check waiver. The fuel leak problem must be fixed however. They will not allow an exemption for a vehicle which may be deemed unsafe to operate.
Here is a link that explains more about the CAP Program. An online application is also available.
California CAP Program - Free $500.00 in smog check related repairs.
While you are completing the CAP application, if your tags are about to expire, you should visit a local DMV office and ask for a 30 day temporary operating permit (TOP). Take the CAP application with you. The DMV typically charges $50.00 for a TOP, but with a CAP application they may waive the fee.