I've had the same thing on my 2016 vantage I bought, when I went to view the car it was there, I was told it would be fixed upon collection. They just reset it and after collecting it lo and behold it comes back on within a day. I then took it to a specialist got an o2 sensor replaced , lo and behold 3 days later it's back. I call up dealership they take it in for a week and replace a different sensor and now we're 4 days later and it's come back again. Is this a regular thing with these cars, I've only just bought it and it's so frustrating. I'm gonna try the fuel cap though, will keep it posted here , also, just for peace of mind, it's rarely anything serious this warning light is it?
thanks

 

You should replace all of the back or front sensors in one go. Not one at a time.

 

I'll speak to the specialist once it's gone in, thank you though I wasn't aware, I'm a novice when it comes to all this stuff , it's my first car like this,
appreciate the reply

 

Try to source the Ford Motorsport version of the O2 sensor instead of the Aston Martin labeled one. Quite a price difference for the same part.