Hello every one,
I own a corolla LX 1.6 automatic transmission 2002 model. Originally car came with 3zz 1600cc engine but i swapped it later with 1nz 1.5 with complete wiring. I kept same exhaust of 3zz with 2 O2 sensors installed in it.
Usually car was driven on cng so fuel consumption was never calculated. For past 1 year car was hardly 5000 km driven.
Recently i changed all plugs,injectors, engine and transmission oil. When driven on petrol tn my village hilly area fuel mileage was around 8-9 max.
Engine checklight was on since i changed my engine.
This time i checked with alot of electricians for this checklight ,after scanning found out the front o2 sensor was bad.
Electricians and mechanic told me front o2 sensor in exhaust bad so i chnaged front o2 sensor but light was still on.
Now today i checked with senior electrician and found out that there is no o2 sensor installed in engine,he just put 1 o2 in engine and engine light was gone.
Now please suggest do putting new o2 sensor in engine will improve my fuel consumption and car performance.
Do i need to change exhaust? Engine sound is not good.
Sensor installed in 3zz exhaust are working or just dummy??
Thanks
