Miss fire on 1998 Honda Passport

My passport back fires when taken to a mechanic and put on the machine it says it has a miss fire we have put different parts on it and that has not helped they say it could be the wire harnesses or the computer

Asked by for the 1998 Honda Passport
You need a better mechanic. A competent diagnostic technician should be able to chase down the root cause of that misfire, so I'd take it somewhere else and be very wary of someone who is recommending changing various parts, trying to find something that works.
2 answers
you need to take your sparkplug and clin them, also the erya wher the sparkplug goes to.