faulty air flow meter
Idle on a 1985 Honda Civic is adjusted through a idle air control valve. This valve is located near the intake. Adjust the valve by either loosen or tightening it.
The idle speed on a 1996 Honda Civic is adjusted using an IACV. The IACV, or idle air control valve, lowers and raises the idle by either being tighten or loosen.
If you have a Civic with the ECO switch turn it off before passing. If not, take it to the dealership you have a problem.
Idle Air Control Valve.
To adjust the idle on a 2005 Honda Civic locate the idle control valve. The IACV and is found near the intake manifold. Open the top of the valve and tighten it to lower the idle or loosen it to raise it.
IF ITS JUST AT IDLE, CHECK YOUR IDLE AIR CONTROL VALVE IF IT HAS ONE.
The Honda Civic loses idle at stop due to not have consistent air flow. The engine will run too lean and cause the car to shut off.
The idle speed on a 2001 Honda Civic is adjusted through the idle air control valve. The valve is located behind the intake manifold. Open the cover using a screwdriver and tighten the valve to lower the idle.
1998 Honda civic lx
Idle Air Temperature sensor.
Because of the loss of backpressure if can affect the idle.