Depress the button on the seat belt buckle. If the belt does not fully retract, pull it out and check for kinks or twists. Then make sure it remains untwisted as it retracts.
NOTE
If a belt does not fully retract, inspect it for kinks and twists. If it is still not retracting properly, have it inspected at an Authorized Mazda Dealer.
Mazda 6 Owners Manual: Cylinder head gasket
CYLINDER HEAD GASKET REPLACEMENT
Warning
Fuel vapor is hazardous. It can very easily ignite, causing
serious injury and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injuries or death and damage. Fuel ...
Mazda 6 Owners Manual: Service cautions
HANDLING INSUFFICIENT REFRIGERANT LEVEL
If an insufficient refrigerant level is detected at troubleshooting,
do not charge (add) the refrigerant. Because an accurate amount of
refrigerant cannot be determined from the pressure indicated on the manifold
gauge, never charge the refrigeran ...