You don't say how much oil was too much, are we talking 0.25 litres too much or 2 litres too much?
Putting too much oil in your engine is very bad as you have discovered, you may have blown seals in the engine due to excessive oil pressure but this wouldn't illuminate your engine management light.
If your car is a diesel then most likely your excessive oil pressure has caused too much oil vapour which has entered your inlet system via the breathers, been taken through the engine and has now clogged up your particle filter (FAP). Your car automatically regenerates the FAP, but will be unable to clean out oil by regeneration. This will cause anti pollution faults.
If its a petrol then it doesn't like trying to burn oil and will cause anti pollution faults because the mixture is all wrong and the computer can't correct the mixture.
Either way if you take it to a dealer they can read the faults and will know what area to look for the problem in.