Knowing which vehicle and what year would be helpful, as there was a mixture of OBD1 an OBD2 used during 91-96,
. 91-93 was OBD1 on traditional small block Chevy Engines.
When the LT1 came out in 94, then through 96, it got a bit complicated, as the software and data streams controlling the ECM varied as the years progressed. So we need the year of your vehicle.