@mirocky .. Dekho mere bhai, CNG installation will only do you good in the short run.
Your car will come up with frequent problems in the course of time. And resale will be very difficult.
Dont do stuff like removing CAT convertor nd stuff, you can get it cleaned though.
Nd Toyota 3S is lying. My passo has never given me below 14km/lit Allah ka shukar hai, chahe men ose jese bhi drive krlun.
But you are suffering a problem many people are with older passos and Witz. My advice will be to sell it if you cant afford it on petrol nd buy some other car.
We also own a 2010 Witz with the same passo 1KR-FE engine, nd the max it gives is 10km/lit.. We tried everything with it but it wont budge. nd Toyota k pass jao tu woh yahi kehte hain k sir yahi mileage hoti hai. Unko bolo meri dusri same gari zada deti hai tu they laugh