Gas mileage drop off

[Jarvis]

I have a 2017 Corolla ECO with 206,000 miles on it.
Looking for info on mpg dropping off from average of 35 to 30
pull throttle body cleaned with CRC, not as dirty as expected, replaced gasket
& assured proper seating. New air filter as well.
Spark plugs probably have 80,000 on them next thing to look at.
One week of driving NO improvement. Any ideas? What about fuel filter??
Anybody?

Thanks Jarvis

 

[Corolla Pilot]

I have a 2017 Corolla ECO with 206,000 miles on it.
Looking for info on mpg dropping off from average of 35 to 30
pull throttle body cleaned with CRC, not as dirty as expected, replaced gasket
& assured proper seating. New air filter as well.
Spark plugs probably have 80,000 on them next thing to look at.
One week of driving NO improvement. Any ideas? What about fuel filter??
Anybody?

Thanks Jarvis

Mass Airflow Sensor may need replaced. O2 sensor is another that influences mpg.
Be sure to use original Nippon/Denso parts.

 

[echarleswhyte]

To change fuel filter you likely have to pull the sending unit out of the gas tank. Not necessarily hard to do but you have to take the back seat out and go through an access panel. Before you do that do as suggested check mass air flow sensor, you can get CRC mass airflow cleaner and try that first, and check O2 sensors.

 

[fishycomics]

Just chiming in on that I have a sender and the tool for it, man was it ever so difficult for me to do with the ebay one I got never had to use it but good to know that the filter is there.