We don't recommend adding any more head gasket sealer to your Saturn L300's water coolant system. Excess head gasket sealer will clog up the radiator and cause overheating problems. We also don't recommend getting a smog check while your Saturn L300 has a leaking head gasket because more than likely the engine is already running above normal engine temperatures and your Saturn's NOx emissions will probably fail the smog test. At this point our recommendation is having your Saturn L300's head gasket replaced. Nox is created when engine combustion temps rise above 2500f. A leaking head gasket will almost always cause increased engine temperatures. If any water (or oil) is leaking into the engine combustion chambers as well the coolant system your Saturn will also produce high HC, and CO.
