Car got an engine warning light,

Lots of advice saying you’ll need to take it to a mechanic to get it diagnosed etc. possibly would cost a couple hundred to diagnose and fix.

Bought a £10 reader from Amazon and the issue was a something to do with the fuel cap not on property.

Lovely job. 

 I had the same issue with a truck a decade ago. My OBF reader has paid for itself many times over! 

 I have mine to my little brother as he is an apprentice HGV mechanic and will get much more use out of it than me.