2003 Honda civic lx automatic 154,000 miles. I recently had problems with misfire, changed all the spark plugs (gaped appropriately) and coils, ran fine but still got misfires (third cylinder) noticed rpm's were low during idle as well. Checked throttle body and sensor both were clean. Checked fuel injectors good condition had them cleaned. Still have low rpm's fortunately no misfire yet as of cleaning them. Will changing the evap canister help with rough idle and prevent future misfires and if is so should I also replace the purge celenoid, I'd imagine the parts have never been replaced, and the vehicle is 13 years old.
Miss fire's kind of car from over two dozen different reasons not always the spark plugs it can be the fuel injection system you could have a vacuum leak you could have a bad valve you could have an intake manifold that's leaking lots of things. So watch my video fixing the misfire an engine Scotty and try all those first
