Hi, this is Rick,
For some time my 98 Chevy S-10 has been misfiring while I deliver mail on my route. I took it to the first garage, and they said that the catalytic converter was gone which would be a 14 hundred dollar job. To get a second opinion, I took my truck to a second garage, and they said the catalytic converter was fine. They said it was misfiring on two cylinders, and they changed the ignition coil for 80 dollars. It seemed to have cleared the problem. But after a couple of weeks I’ve noticed some very slight symptoms my truck made when it began misfiring some time ago before it got worse. At this time, it has been running great except that when I’m driving on the highway there’s a slight sputter but not the loss of acceleration as before. I hope its just paranoia, but I’m thinking that the ignition coil may be failing again.
My first recommendation is to stay away from garage #1. Second, post the specifics; engine, etc., of the truck.
And, go to an auto parts store that will do a free scan of your OBD system for stored trouble codes. Auto Zone may have discontinued this free service, but IIRC, Advance Auto and some other parts stores will still do this for free. Then, post the codes (format is along the lines of P1234), and someone in this forum will be able to give you specific advice regarding those trouble codes.