Excesive fuel comsuption

I have a used Nissan March Japan model, 1.240 cc. engine CR12DE automatic transmission made in 2005, the problem is that it have a poor fuel comsuption 10 km/lt in city, I changed the spark plugs for a Denso Iridium IKH16, the air filter is new, the fuel filter is in the tank and there is not in my country is very hard to find, I am from Iquique-Chile South America and the steering was changed from left to right, Do you think that could be the oxygen sensor? anybody can be so kind to help me please.

Greetings Juan.
 
Back
Top