Computer Code Reader 94 SW2

You can go with the more expensive types from any garden variety Auto Parts store. A typical Tech II tool can cost in the hundreds or more. I believe JC Whitney also sells a GM diagnostic tool for less, these are the ones with the LCD display that shows the code, clears it, etc. Not necessary for OBDI computers. I use an inexpensive GM code reader from Innova I bought from WallyMart for the older Saturns. It comes with a book showing all codes. Costs about $25. Has worked great for me so far! For OBDII, Harbor Freight sells a GM OBDII code reader for about $40.