o2bird

I tried searching and couldnt find anything. I want to switch over to a standalone engine management, my problem is OBD2 emissions here in arizona. I need to have a working check engine light. Can you keep the stock computer for the gauge cluster and use the BS3 for everything else? All it has to do is come on at key on and go off after startup and show no codes. also if i have to keep the stock PCM i want to at least wire everything else from scratch. Only thing i can think of making problems is the vats. I believe the BCM needs to speak to the PCM in oreder for start up. Can this be bypassed with HPtuners? Hope that all made sense. Thanks in advance.