Mazda 6 Service Manual: No.7 slow return to idle

No.6 cranks normally but will not start

No.8 engine runs rough/rolling idle

Other materials:

Mazda 6 Service Manual: Engine Exhaust (Carbon monoxide)
WARNING Do not drive your vehicle if you smell exhaust gas inside the vehicle: Engine exhaust gas is dangerous. This gas contains carbon monoxide (CO), which is colorless, odorless, and poisonous. When inhaled, it can cause loss of consciousness and death. If you smell exhaust gas inside the ...

Mazda 6 Service Manual: Warning Light and Brake Pad Wear Indicator
Warning Light The warning light turns on when the system has a malfunction. Refer to Warning Indication/Warning Lights Brake Pad Wear Indicator When the disc brake pads become worn, the built-in wear indicators contact the disc plates. This causes a screeching noise to warn that the pads shoul ...