Some of these east-west mounted V6s can be very difficult to access the rear bank of cylinders. A quality workshop manual will detail how to remove the rear rocker cover and spark plugs, and there are also some very good online tutorials you can tap into.

The fact that no error codes have been logged suggests that the spark plugs are at fault. In some cases, on-board computers can detect a bad ignition lead or coil, but will not recognise a dud spark plug. But oil leaks can also cause misfires if the oil gets into contact with the leads or spark plug contacts, too, so the leaks need to be fixed as well. The spark plug theory is also supported by the fact that the miss is occurring under load, which is when an ignition system is working its hardest.

There shouldn't be any issue with leaving the maintenance charger connected to the battery, and other than the inconvenience if having to reset the clocks and radios there shouldn't be any issue caused by disconnecting the battery. After all you have to disconnect the battery when changing to a new one.

YOU are not alone. Many people say the Magna/Verada was a good car, but they had an image of it being boring. If Mitsubishi had somehow been able to race it against the Falcon or Commodore it might well have been able to change its reputation.