if you take the bulb out they can't physically dismantle stuff to see if its still in place but if they are switched on they will recognise that there is no airbag light startup.
I can honestly say I've never tried on a 156 but other models of cars I've had I know that when the airbag bulb is removed a warning siren is heard to inform the user that a safety system is faulty.
I would honestly invest some time in sorting the fault, they are designed to save your life after all. common faults on airbags are connectors under the seats, connectors on the bottom of the B pillar for the inertia reel seatbelts and front curtain airbag connectors that are in the boot, behind the carpet on drivers side (UK car).
as for the remap business, whats the point? people just just resort to piggyback ECUs and tuning boxes but the tuning boxes instead of having a bog standard map will have a more customised map to give full remap style performance. they will find ways of getting around it anyway.
i can't see how it would be detectable either, the only way I can think is that when you first connect to the ECU it gives the engine software version date on it which could be a give away. only other way to tell would be to stick it on a rolling road and see what kind of power things are kicking out but even then its no a sure fire way of telling.
1999 156 1.8TS Sport Pack 3
2001 166 3.0 V6 24V Super
2003 156 GTA 3.2 V6 24V
2005 156 1.9 JTDM-Jet Sport
2008 159 1.9 JTDM Lusso
1997 GTV 2.0TS Lusso
2001 147 1.6TS Lusso
Last edited by Artermis; 11-11-10 at 04:54.