I know I have a bad o2 sensor, and I have one on order. The wierd thing that I just noticed today is that my instentaneous l/100 km is 8.5-11.5 (around 23-27mpg) , usually it is 0. would this have anything to do with the o2 sensor, or are there any other things that i can check while waiting for the o2 sensor. i love tinkering on the car :P

 

No idea, the cluster takes info from ECM which gets it from the MAF sensor and O2 sensors, so it may contribute to the MPG display.

 

MPG should be 0 at idle. Cant go any miles in any amount of time when you are not moving.

 

the car takes the amount of fuel you are using and your MPH and figures out your MPG. if your MPH = 0 then your MPG will also = 0