Increased fuel consumption — what’s the reason?
INFINITI FX 4.5 Allrad (232 kw / 316 hp) (01.2003 - 12.2008)

Increased fuel consumption is often caused by worn/faulty spark plugs. In this case the ignition of the fuel-air mixture is impaired. Contaminated catalytic converter may result in a sudden increase in fuel consumption. Other possible causes are faulty injectors and fuel leak from the fuel line. The latter often comes with a strong fuel odour while driving. There are many reasons for this, so it is difficult to find the right one without inspecting the vehicle.