Mazda 6 Service Manual: No.6 cranks normally but will not start

No.5 engine stalls-after start/at idle

No.7 slow return to idle

Other materials:

Mazda 6 Service Manual: General procedures
PRECAUTION (SUSPENSION) Wheels and Tires Removal/Installation When a wheel is installed, tighten it to 88-118 N·m {9.0-12.0 kgf·m, 65.0-87.0 ft·lbf}. Suspension Links Removal/Installation Tighten any part of the suspension that uses rubber bushings only after the vehicle has been lowered ...

Mazda 6 Service Manual: High-mount brake light removal/installation
4SD In-vehicle-type 1. Disconnect the negative battery cable. 2. Remove in the order indicated in the table. 3. Install in the reverse order of removal. Rear spoiler type 1. Disconnect the negative battery cable. 2. Remove the rear spoiler. (See REAR SPOILER REMOVAL/INSTALLATION) 3. Remo ...