If you have very bad poor IDLE on your Honda civic the first thing that you have to try:
1. Check coolant level. .
Plug troubleshoting odb2 computer (diagnostic tool) and read error codes if it will say that you have P0300 P0301 etc. misfire
2. Check your spark plugs
3. Check ignition Coils
sometimes it will or can detect crankshaft sensor position wrong sometimes not
anyway !!!
if it’s still does the same consider replacing your crankshaft and camshaft sensors they are very important because they determine position of the engine.
Post time: Jun-13-2017