obd 1 system ,the code reader i have is made by "actron" just your plain jane basic reader that has led's and a piezo speaker....29.00 at advance auto.there is another one that they sell for about $10-20 more (which i did not see at the time i bought mine ) that has a lcd display to read system code .....imho much better than trying to make sence out of code from beeps and lights flashes.
look at advance auto's web site and see if they still sell that reader .in my opion i would go ahead and spend the little extra on it compared to the basic actron reader i have ....will make your life alot easier when doing codes.