How big a risk is “amber EML after driving a while”?

[VXRFan]

I’m brand-new to the forum. I’m looking to buy an Astra GTC. A dealer is selling an 1.6T SRi 2013 and describes the only issue with the car being that the EML comes on after driving for a while. How big a risk is buying a car like that? Of course, I cannot get the DTC read out to know what it may be.

I was thinking, wrong stop/start battery fitted, spark plugs, coil pack, MAF sensor, a split hose somewhere, so could be something I can fix cheaply myself? If so, it would be a fair price for an otherwise great looking and spec car.

But anyone have experience that can give me a better feel for whether this (EML on after driving a while, then resets when restarted) could be a pricey and disastrous  issue, full engine fail etc?