A common fault I deal with a lot is engines misfire and running rough concerns. Today it was a Holden Cruze in Nerang. The complaint was running rough and lacking power. I found this engine to running on 3 cylinders not 4, this was quickly diagnosed with the scan tool.
Replacement of the coil pack was needed. The coil pack is the part that creates the voltage to fire spark plugs. This is a sealed part with no maintenance required, it only replaced when it fails. Unfortunately this can be without warning. The coilpack was removed and replaced with a new unit. With this vehicle, the coil pack for all 4 spark plugs is a single unit unlike most other vehicles which have individual coil packs (coil per spark plug).
I recommend replacing spark plugs at the same time as they can be fouled by the running rough fault. Finally after the parts have been changed all codes in the computer are cleared with the scan tool. This is so if any new codes come up we know they are new and not from this fault or a previous one.
The client was very happy with the quick repair while they were at work, saving them the hassle of having to take the car to a workshop. If your vehicle has a misfire or is running badly call your local mobile mechanic.