Strange MPG

[Speedy Steve]

Ok this all started a few weeks back i was driving home from work and i noticed my fuel gauge had gone from half full to full and the DIS said i was going to get a total of near on 900 miles out of the tank. I drove the rest of the way home fairly heavy footed and when i got home it was back down to just under half. Since then my current MPG on the DIS is very sensitive as soon as i lift of the throttle it says --- which is confusing. i can still get 360 miles to a tank if i drive fairly steady. Lastly at the MOT i was told it was very difficult to pass the emissions although i didnt get a read out for some reason.

Any body had anything like this and any idea what it could be?

 

[A3Tom]

I only get --- on the DIS when its in current MPG mode etc, not average or on miles left in the tank.

Is yours doing it on miles left in the tank when you lift off?.

 

[Speedy Steve]

Yeah just in current. although miles left is very sensitve more than it used to be

 

[Dani_B19]

Isnt it todo with a faulty fuel sendor in the tank?

 

[Speedy Steve]

Would that effect my emissions?

 

[Nilz]

Emissions is probably being affected by the lambda sensor, also when you take your foot off, it will --- out, as it has nothing to record in a form of MPG, as soon as you put your foot back on it will pick up again, if that makes sense??

Might be worth getting the car on vagcom to see if it brings up any faults.

 

[Speedy Steve]

i think vagcom will have to be purchased soon is it hard to use and understand?

 

[Nilz]

Dont think its that hard to use or understand, all the codes etc can be found quite easily on the net, so you shouldnt have much of a prob, PM NHN if you need it as he can supply you with it and give you some advise on it too.