My civic hesitates/jerks while driving. I’ve taken it to several mechanics, the local Hondal dealer, and the best retired Honda mechanic around; no one can tell me whats wrong although I do have to say no one has really checked it out very thoroughly. The check engine light does not come one, it seems to run worse when the humidity is up, and it runs great in cold weather. I’ve run gas cleaner throught it, had an 02 sensor put on, put non-ethanol gas in it. No difference in how it runs. Sometimes it runs really well in the first 5 minutes of starting. It idles fine . . any suggestions?
So the check engine light isn’t on . . . fine
Did anybody hook up a scanner and look for stored fault codes?
Did anybody hook up a scanner and spend some time looking at live data?
Stick shift or auto?
Has anybody checked if the engine coolant temperature sensor and the map sensor are accurate?
TO db4690: No, No, No, stick shift, and no . . . mechanics don’t seem to want to be bothered. They all tell me “oh just drive it until the engine light comes on”.
You need to keep looking. You may have to find an older mechanic who has patience and likes a diagnostic challenge