Fuel injector replacement

[Martin8226]

I need some help, one of my fuel injectors is messed up (broken-causing misfires and heavy ilding) do the fuel injectors need recoding if you swap them out? 

It needs replaced and I can't afford to go through Audi to do it (power steering pump and fuel injector parts plus labor = £1500) so trying to do it on the cheaper side (get part off of eBay and fit it) but I need to know if they need recoded or not? 

Any help or advice will be greatly appreciated