I own a vehicle, a Japanese Toyota Passo 2015 Model, 3 Cylinder 1KR engine of 996 CC. I am facing an issue with my car. Last month I went to a workshop and asked him to clean the Fuel injectors, Catalytic converter and oxygen sensor. He has an ultrasonic machine to clean the Injector and sensor. He cleaned the sensor and injected it into the car. After driving 50 KM my car started knocking and after a long trip of 800KM I observed that my car engine oil has just 0.5 liter remaining in the car. Then I visited him and he swapped the injector with 1 & 3 and my car stopped knocking 98%. But one of the spark plugs is still going to blackened and oil is continuously reducing like in 2000 KM 1.5 liter is remaining instead of 3.25 L. We also check that each cylinder compression 1st one was at 180, 2nd one was at 180 while the 3rd one was at 210 and the 3rd cylinder is the one whose spark plug is blackned only while the rest of two cylinders plugs are orange. My Mechanic is saying that your engine is weak but I do not agree with him as before doing all this my car was running very normal. 

 

Can you please advise me what could be the reason why engine oil is reducing? Before all this activity my car was running normal and not reducing the oil. I shall be very thankful to you.

 

Total Engine running : 180,000

Model 2015

Engine 1KRFE 

Transmission Automatic CVT FE

    

If you need any further information please let me know.