My 99 EJ6 coupe has immobiliser issues- but I don’t have the red master key and can’t get it. Honda have said they don’t have the facilities to replace this, or even replace the whole locking system on the car as it’s all been discontinued- meaning my car is dead in the water. Any suggestions how to overcome the immobiliser? Change ECU? Anything at all will be appreciated! 

You could buy an immobilise unit from eBay which should come with keys and barrel locks, etc

Not too expensive and not too difficult to fit and no need to reprogramme