START/STOP Error with Misfiring

[SEATsupersonic]

As the title states, I am currently experiencing an intermittent start/stop error on my SEAT Leon FR Mk4 E-TSI DSG 70 plate 56k miles.

The issue is intermittent and does not appear each time the car starts up. When it does appear, it will clear after a few seconds, and it has been accompanied on one occasion by a flashing engine light and engine misfiring when idling. The car has just passed its MOT and had a recent full service, including spark plug change. The problem appeared after the service, but before the MOT. No MOT advisories related to this problem, only a wheel bearing problem which I self-identified anyway.

I have asked the garage to look over the engine misfiring, but with no avail in finding the cause in issue. I have an OBD2 reader, but the garage cleared the codes, and it hasn't misfired since, so I can't identify any codes. The start/stop error appeared again this morning, then cleared itself off the dashboard. I'll scan the car again tonight when I get back, to locate any errors related to the start/stop error that appeared this morning.

Any ideas? I'm not really up for taking it to a dealership any time soon, considering their initial diagnostic fee is £160. Absurd. Thanks in advance.

 

[smiffypr]

"full service, including spark plug change. The problem appeared after the service"
I don't know your engine, but I have seen on many cars that have just been serviced where one or more HT leads is not fully home.
Are the plug leads or coil-overs all sitting at the same height?
If everything is perfect there, I would suspect a faulty or damaged plug.

 

[SEATsupersonic]

"full service, including spark plug change. The problem appeared after the service"
I don't know your engine, but I have seen on many cars that have just been serviced where one or more HT leads is not fully home.
Are the plug leads or coil-overs all sitting at the same height?
If everything is perfect there, I would suspect a faulty or damaged plug.Thanks

Thanks for your response and help. I've returned back to the garage since, and they claim they've checked over things including some of what you have mentioned. I don't know if they have checked the plugs themselves directly, but I would imagine and hope they have. The misfires were on all cylinders, not just individual ones.