S200 blue box question and check engine light

[turbocivic]

real simple question here. With a correctly working S200 system, can you still pull the check engine codes via the 2 wire jumper? (laptop not available!))

Once a S200 system has been set up and tuned, is any important info store within the blue box? Could you swap in a friends blue box to test if you thought you had a bad blue box? Both cars are N/A, but one is tuned with E85.

Thanks

[Spunkster]

yes and yes