Hope you're all doing fantastic!
I recently bought a 2nd hand Daihatsu Move Custom 2011 Model (2014 Imported) without the ECO IDLE function.
This is gonna take some little reading so bear with me
1. When i got the car 2 months ago, its check light was on and was giving me around 10Km/L Fuel Mileage. Checking from the OBDII showed that the "Front O2 Sensor" has some issue with the Heating or something like that
2. Tried changing the O2 Sensor two times from Bilal Gunj, no luck.
3. Washed the Front Cat Bag (where the Front O2 Sensor lies) with Acid.
4. The Check light was gone, noticed some better pick, but the Mileage issue stayed. (11-12KM/L this time)
5. After 40 Kms, got the check light again. This time (on my own OBDII device bought from Aliexpress, its so handy in situations like these) I got the "Rear O2 Sensor's" Heating problem
6. Changed the Rear O2 Sensor TWICE from Bilal Gunj (also washed the Rear Cat Bag, i don't know if there is a rear one but the Mechanic said he did clean it with Acid again)
7. (Since the new O2 Sensor takes a time to check its functionality) The first 40Kms were great. Noticed great accelerations and fuel mileage was around 18Km/L (From Johar Town to Cavalry Ground).
8. But, after driving about 40Kms again, the check light again came on.
9. This time, it didn't report any heating issue. Rather "P0136 - Powertrain : Rear O2 Sensor Malfunction"
10. The fuel average is still almost the same, i.e 16-18Km/L on routes where I used to get 11-12Km/L.
Note: The first time, when I changed the Front O2 Sensor and it was still faulty, it was taken out from a properly functioning Daihatsu Move 2011, the faulty was put in that. The other car worked great and mine still didn't work (lol)
What can be the cause of this issue? Is the person who I'm checking the Cat Converter and O2 Sensor stuff is doing the right thing or does my car have any other issues?
Thank you for reading so patiently! I look forward to your response! Thank you!