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: Dynamic Stability Control (DSC)
The Dynamic Stability Control (DSC) automatically controls braking and engine torque in conjunction with systems such as ABS and TCS to help control side slip when driving on slippery surfaces, or during sudden or evasive maneuvering, enhancing vehicle safety. Refer to ABS and TCS. DSC opera ...

Mazda 6 Service Manual: Precautions before welding
Vehicles have various electrical parts. To protect the parts from excessive current generated when welding, be sure to perform the following procedure. 1. Turn the ignition switch to the LOCK position. 2. Disconnect the battery cables. 3. Securely connect the welding machine to the ground nea ...