Marine OBD Cable for MEFI5 Systems and LT1 equipped cars are

and LT1 equipped cars are a few

and MEFI-4

This cable includes one Female (sockets) connector to plug into your vehicle connected to four Male (pins) bulkhead connectors

Other newer GM cars and trucks may work the same way

Some competing systems will only allow you to monitor the performance of your boat or off-road vehicle's engine controller and reset engine trouble codes

Marine OBD Cable for MEFI5 Systems and LT1 equipped cars areUse this cable with the MEFI 5 Scan or MEFI 5 Scan & Tune systems to interface with vehicles using the flat 6 pin marine diagnostic connector. The MEFI 5 kits already come with an interface cable for either an OBD2 style connector or a 6 pin flat marine OBD connector. Use this cable if your kit has a OBD2 style connector and you need a marine 6 pin style interface.