look under the lower part of the passenger under side up inside dash next to the door and find a 2 wire blue plug. get a wire or paper clip ans stick in one then jump to the other. cut on switch then it will blink the codes. the long blinks are 10 and short count as 1. so 2 long and 3 short would be 23, if you then google this code it would come up as knock sensor. so count the codes cause some times theres more than one till it starts over then google them or look in a chilton for that year car. good luck