Rep Power: 0

I'm a Disabled Veteran who owns a 2000 Honda Civic EX Coupe D16Y8. The engine was totally rebuilt in 2015 (142000) and now in 2020 has 188118 miles. I use 5W-30 Full Synthetic oil. In July 2019 my gas mileage went from 27 mpg to 13 mpg. I found the PCV hose clogged and would have replaced it myself but my hands don't work very well. I took my car to the local Honda dealership. They replaced the PCV tube, PCV valve and oil changed since they had to remove the intake manifold. The check engine light P0302 - misfire first showed up in late October 2019. My brother helped me change the spark plugs (NGK), new spark plug cables and new distributor. The check engine light was cleared and I drove 240 miles and the check engine light came back up indicating P0302. My brother in law suggested I take it to the dealership and have them check the timing belt, readjust the valves and clear the code again. Three days later the light is back on with P0302. I ordered a block tester kit from Amazon for about 38 dollars to check for a possible blown head gasket. Well I was relieved to find it wasn't a blown head gasket. My Uncle suggested Seafoam which I added 14 ounces to my fuel tank and 4 ounces to my oil. The check engine light went off by itself and the car is running like a champ. January 17th, 2020 check engine light again P0302. Changed the fuel filter. In all this time I have only had a rough idle which disappears in seconds after starting the car. No loss of power, no surging, mileage has improved to 29 mpg. AND the check engine light is back on. Please help.