1998 Civic Dx 1.6L Low Idle Issue

Hey, I figured out that my low idle problem, goes away with head lights on or A/C on or even hot air. So car without headlights or air on. Idles at a stop around 300-500 rpm sometimes lower that it even shares.
When I have the headlights on or air on at full blast it idles normal at a stop. Around 700 and doesn’t shake.

Things I replaced are:

  • PCV Vavle
  • Idle Air Control Valve
  • Checks TPS working and calibrated(.48 TB closed and 4.50 TB Wot.
  • changed map sensor
  • checks O2 sensor by disconnecting them and running the car and it ran the same with the same problem

If anyone has an idea on what it is, I’ll really appreciate it. Already been going on with a month with this issue and I can’t seem to find the issue.

I see you’ve already replace the iac and calibrated the tps

But have you cleaned the throttle body yet?

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Yes, I cleaned my original throttle body and I even replaced for a different one. Nothing changed

I really neeed help

You could just always drive with the lights on, like I do. It makes your car more visible, even during the day.

My ‘98 Civic has always idled low, at least for the past decade, but I never worried about it because it means I’m saving gas.

It looks like you haven’t thrown parts at the ignition system yet (distributor, etc.). You could try that next if they’re not relatively new.

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Cap and rotor are new

Have the plugs and wires been changed? How about cleaning the EGR?

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Yeah changed them like a year ago

NGK Blue Wires and NGK Idrium IX spark plug

Have you tried an idle relearn procedure?

With all electrical systems turned off, start the engine and let it idle for 10 minutes.

Don’t touch the steering wheel nor the brake pedal during the procedure.

Tester

Yes I tried it a couple times but I don’t know if I’m doing it the right way.
Do you happen to know the proper way I have a automatic 1998 civic dx 1.6L ?