Engine light

[wilko]

Ad spark plugs coil and fuel injector fitted but engine light still on and still miss firing in 1 cylinder 

[Vauxhall Owners Club]

only other thing it can be is the wiring to either the coil or the injector

Inspect the wiring and the plugs onto each component for security, damage or corrosion

Alternatively, see if swapping the components to another cylinder puts the fault onto that cylinder instead