Bad O2 SENSOR?

[rscivil]

All of a sudden, I've noticed that im getting lower gas mileage than before from my honda city 2006. I've already changed the oil, replaced air filter and spark plugs. Right now im getting 9km/ltr. Could it be my o2 sensor is defective?

[CivicVTi]

Symptoms of a dying O2 sensor would be erratic idling. If the engine idles normally, then this sensor is ok.

Check your tires if they have correct pressure. Check your trunk and discard heavy stuff that your don't need to save on weight. If you drive with a heavy foot on the accelerator pedal, then perhaps its time to relearn how to drive economically.

If your regularly encounter stop and go traffic, this can greatly contribute to poor fuel economy.

[rscivil]

Thanks for the reply.. Normal naman idling ng city ko, pero sa simula nsa 1.2k siguro yun, kpg nakalagay pa yung cold engine indicator ba yun. Pero nawawala naman agad, bumababa idling below 1k. Is it possible na sa ecu ung problema? Malaki ba ang parte ng ecu sa fuel economy ng sasakyan?

[CivicVTi]

Thanks for the reply.. Normal naman idling ng city ko, pero sa simula nsa 1.2k siguro yun, kpg nakalagay pa yung cold engine indicator ba yun. Pero nawawala naman agad, bumababa idling below 1k. Is it possible na sa ecu ung problema? Malaki ba ang parte ng ecu sa fuel economy ng sasakyan?

Normal lang na mataas ang idle sa umaga, pwede umabot hangang 1,500rpm. After ng ilang minuto bababa din around 750-800rpm.

[rscivil]

Lalabas naman siguro yung "malfunction indicator" kung my problema o2 sensor. Titingnan ko nga kung makakaya 300km sa half full tank ng city ko.