does the light look like an engine outline or say TWC? if so there is a pigtail harness just to the outside of the battery, it has 6 holes and is capped with a black cover. with the holes facing you, (wires away), lock tab on top jump the bottom left 2 holes and turn key switch on. blink code 1 is most common. you will need to set the idle speed to 800-850 and adjust the injector rate to 4-12 ms. (set the idle and set the l/p reg the best it will run and then lean untill rpm just starts to drop) you may need to remove the tamper plug on the regulator. you can clear this code by removing the TWC fuse or battery cable. code 3 is broken wires at the vacuum sensor. you can check puylse rate with meter with frequency. "tricky"