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: Drive Selection (Some models)
Drive selection is a system to switch the vehicle's drive mode. When the sport mode is selected, vehicle's response against accelerator operation is enhanced. This provides additional quick acceleration which may be needed to safely make maneuvers such as lane changes, merging onto freeways, o ...

Mazda 6 Service Manual: Transaxle range (tr) switch adjustment
1. Disconnect the negative battery cable. 2. Remove the air cleaner component. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.) Caution Water or foreign objects entering the connector can cause a poor connection or corrosion. Be sure not to drop water or foreign objects on the connector w ...