mystikal-vti

ok guys here it is a mate of mine has a 95 jdm eg sir now it runs ok on his ecu but when we stick any other ecu even from another sir it brings up a fault on the ecu which is the 22 Variable Valve Timing & Valve Lift Electronic Control Pressure Switch (VTEC Pressure Switch), but then i go and look for it on the engine and it dont have 1 any one any idea wats wrong and aswell we dynoed it and as song as the vtec kicks the hp drops right down for a sec then shoots straight back up , any ideas