NPN Transistor used when converting 1720 and 1980 boards to VTEC. Used at position Q26. This transistor is labeled D1423. On p05 ECU's, this NPN transistor is used at Q30 to convert to a 4-wire O2 sensor. This transistor is also used at board location Q37 for ECU's that will be used with the Hondata CPR kit.