Timing chain

Hello I’m new to forum
I’ve a 2016 2.0l sport timing chain had started to get rattly on my wife as she was driving it started to knock with oil warning light and no brakes, she pulled over and recovered home timing chain has stretched on it fault codes read no engine vacum would this be from the chain stretched? We have removed engine have new chain and guides ready to replace head is away to get tested and valves checked, is there anything else I should think of replacing or checking when the engines out does oil pump give bother
Thanks

Replacing the oil pump can't do any harm. These engines are known to suffer oil dilution, so the pump will have been running with questionable lubrication.