Possible Code 13?

Since the car uses OBD 1, we plugged in an attachment for it that fits well (I believe it is like jumping the t1 and e1). Anyways the check engine flashes once and then three times, leading to an assumption of it being code 13. Car has recently had its timing belt fixed and positioned properly, the ignition coils have also been replaced as well as some other things. The check engine has seen to go away randomly when changing gears from neutral to drive and back. The car does this one thing at times where under heavy flooring it sometimes jerks other times it drives perfectly fine and reaches speeds of over 200 km.