Totally stock Civic DX with the SOHC 1.6L motor. The engine idles very low and rough and sometimes stalls, only when hot. It runs fine when cold and there are no driveability problems. it runs fine, except at idle. Also the check engine idiot light is NOT on.

Any idea where to start?

Plugs, cap, rotor, wires, fuel filter are all good. I am thinking O2 sensors. They were replaced about 50K ago.

 

I would start by cleaning out your IACV. After that I would see if your EGR is clogged/stuck open. I'm not exactly sure if the DX has the EGR, but I believe all non-vtec motors do.

Good luck-

K