Engine diagnostics are performed by a mechanic when the engine isn't working at optimal performance. The mechanic will begin by plugging into the onboard computer of the vehicle in order to receive codes that correspond to different issues. Each code is interpreted by the mechanic who then determines what the cost of parts and labor will be to fix the issue(s). An engine tune-up is the scheduled engine check-up for a vehicle. It is recommended to have a tune-up every 25,000 to
