Was driving home from work today - low on petrol, so I was doing low revs in high gears, which isnt my normal driving style in all honesty.

After about half an hours driving, the engine light started flashing... as I started panicking and looking for somewhere to pull over and cry , it stopped flashing, so I just kept driving till I got home.

Does anyone know what it is/ could be ?
If I get it pluged into one of those fault machines - will it know what the problem is, even though the light isnt on anymore?

I have a sports air filter that is a bit muddy - dont know if this would have affected it. Also did some driving through sand yesterday... if this got flicked into the air filter would it have got through?

I recently had a little mishap where my underside scraped along mud - would this possibly have covered/ damaged a sensor somewhere?

Please advise