Fault Codes 303 and 203- Injector Circuit and Cylinder 3 Misfire

[Shantijoe]

Hello

My post a few days ago promted me to buy a fault reader and the results are above.
I can't drive 200 miles home so have taken it to a garage I don't know which leaves me nervous...

Can anyone suggest common faults such as Spark Plugs? I don't want to be charged for a Fuel Injector I don't need and my pension can't afford! The 2012 ES has only 40K miles,

Thanks for any help from a nervous old joe