@harry vederci sorry, you're ahead of many with the battery, it's state of charge and charging the battery with a charger, and not thinking a 20-mile journey is a long run.
As has been put a generic code reader might not be too accurate but if the error codes have gone it done it's job if not too accurately. Also as put always bear in mind there can be more than one issue and/or cause(s) of issues(s). Error codes should only be taken as possible pointers in the diagnostics process, a good scan might be pointing at the cause or just blaming the messenger.
A 120 miles run is a good run but not always a good blow -out (or through) run but you'd know what it was like, I've done choking runs and smooth flowing empty roads runs in Scotland and England.
My wife had a 2008 GM diesel before the Fabia and the few times I drove it and very few times filled it with fuel I put V-Power diesel in and could see the evidence of the different in the rear view mirrors, I know others don't accept this for various reasons, often monetary as with my wife.
Until you have a new filter to compare with it can be difficult to see how dirty an existing air filter can be, I'd also wipe out the inside of the filter box and trunking as much as sensible and possible.
If any codes return as has already been put it could be wiring or connections, a higher level scan tool make give you more information about this but sometimes just using your own personal diagnostic tools of your human senses and mind can do more and better so always worth a look-see, especially whilst doing things like changing the air filter, look before and after doing the job.
What year is your car, perhaps there might be something about why the the cruise control function can't be set at the moment.