1. If not as specified, loosen the fuel-filler lid installation bolts, and reposition the fuel-filler lid.
2. Measure the gap and height between the fuel-filler lid and the body.
Clearance
a: 1.7-3.7 mm {0.067-0.145 in} b: -0.5-1.5 mm {-0.019-0.059 in}
3. Tighten the bolts.

Fuel-filler lid and opener removal/installation
BumperMazda 6 Service Manual: STEP 3: Contact Better Business Bureau (BBB)
Mazda North American Operations realizes that mutual agreement on some issues
may not be possible. As a final step to ensure that your concerns are being fairly
considered, Mazda North American Operations has agreed to participate in a dispute
settlement program administered by the Better Busi ...
Mazda 6 Service Manual: No.8 brake system warning light stays on more than 4 seconds with ignition
switch on
Diagnostic procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure co ...