Greetings and Welcome to Just answer.
I will do my best to assist you. When you are finished please click on accept only if you are satisfied. I don't get paid unless you do.Please do not accept if you cannot leave positive feedback. I don't know if you are a tech or a just working on your own vehicle so we may have to fine tune the answer. I only know as much about your problem as you have told me in your post, so my answers will be based on what you tell me so please add all the details you can.
This is likely a bad ignition module. It mounts near the coil on the passengers side of the engine.
What type of hand held computer? DOes it just to codes?