Scan tools

Depends on if you're doing this professionally or DIYer

For a shop, where you don't know what's coming through the door next, not all scanners are created equal.

There are 7 digit trouble codes now a days, and a better, more expensive scanner can do it all. There are a lot of manufacturer specific enhanced codes "EOBD2 codes" that we didn't have pre 2010.

Obd 2 might have the same connector from 96 and up but it has evolved and is definitely not what it was in 1996. We have moved a long way from the old KOEO/KOER scans to the newer SAE J-2012DA protocol. Most people don't know about OBD 1.5, so it can get pretty deep.

So it depends what you're working on and If you're doing it professionally or not.