99 Civic LX check engine lite came on - engine is missing

I have two cars and rarely drive this one. Just started driving it today to home Depot to round out the tires after sitting 3 months. On my way home the check engine lite came on. I will know more when I put OBD 2 tester on it. It started missing on the way home and felt like when I accelerated the car it would feel for a second like you were losing power and then be fine. But it would do this repeatedly. Lose power for a second and then the power came back. I pulled into the driveway and it was idling at 1500rpm. I put it in park and when I would raise the rpm inside the car from 1500 rpm it would miss until I got to 2000 rpm and then it would smooth out with no miss. I opened the hood and raised rpm by hand and it sounded like I could hear the pistons knocking when it would miss like the timing was off and then when it stopped missing at 2000 rpm and higher I could not hear the pistons.
I turned off the motor and restarted it. It ran fine again and idled fine again. I went for a drive and it was fine accelerating. I stopped at my buddys house and it idled fine. When I left after 10 minutes it started missing again. Car has 143,000 miles on it,changed distributor cap,rotor,spark plugs at 100,000 miles. Both O2 sensors have been changed one at 101,000 miles and the other at 139,000 miles.I have never changed distributor. Car has been well maintained by me and I have all records. Will hopefully know more when my buddy lends me his tester.Any thoughts?