Fuel economy is decreased

I was apparently having a similar issue with my 2014 JDM Aqua. that I bought in Jan 2018, didn't have any error but my fuel economy came down from 22 km/L during winter month (reading after full tank) to around 15 km/L in summer. Now in Ramazan I am on leave from my job, and avoid running around in fasting month, I am driving my car only on running small errands for 2-4 km with 10- 20 minutes idling waiting in the car with running AC (while my wife is doing some quick everyday shopping), my "trip fuel average" has come down to a horrible 7-10 km/L.
I therefor think that fuel economy has a lot to do with
1- the extremely hot weather with temp between 35- 45 Celsius with AC running full time against high temp.
2- Driving on congested city roads on short trips which is a sure fuel economy killer.
3- Lack of awareness about driving style for fuel economy.
4- Lack of accurate reading for fuel consumption on a single trip

Aqua gives poor economy if driven for short trips in congested city roads in Pakistan's very hot weather with AC, while on open non congested city roads, say during night time if driven avoiding rapid acceleration, the economy can easily go up to 35 km/ liter. I am saying this from my own experience using trip meter set to show ," trip average" which few people use or even know about. You can display trip"s average consumption when you press trip button repeatedly after the display shows up trip A, then trip B, and on third press you get 'trip average'. With ' remaining km fuel'. Take note of this reading if you are driving under different conditions like me.

So in short make a note of your trip average during various conditions if the average is good on some trips & bad on short trips, there is noting wrong with your car, but if your average is bad especially on longer trips on open non congested roads there is something of concern. get your car checked for dirty catalytic converter etc.

 

What is the error code? Or even the error. Fuel economy can drop because of many factors.

Tire Pressure being too low creating drag, cooler temperatures not allowing the engine to warm up efficiently, hotter temperatures requiring the AC to be run, a dirty or blocked fan vent in the back seat.

Most errors for hybrid system that I see on the forum are due to the last one. Either the fan is being blocked by something, or it's excessively dirty. These are quick and easy checks/maintenance to perform. I'd start there before changing out a throttle body.

 

Unless there is a code thrown by the car, nothing will be wrong.
Hybrid cars are quite different from conventional ones, roadside mechanics dont have the tools & knowledge to work on hybrids. Stay away.
Relax........
Use recommended 0w-20 oil, Toyota original air & oil filters. Milage will improve as the weather turns cooler.

Just enjoy your car.