Hi Everyone,

I recently bought a A3 2.0T Quattro 2005, but I am having some trouble with my MPG.

It currently averages around 16mpg, even with a light foot. When I put my foot down I get between 7-10mpg.

The person I bought the car from told me that the lambda sensor needs to be changed. Since then I have scanned the car with a OBD2 reader.

I got a code for a faulty N80 sensor, but nothing for the lamba sensor.

It also looks like there isn’t an air filter inside the air box.

Would the low mpg be caused by a N80 valve and incorrect airflow? Or is it likely that the lambda sensor does need to be changed but isn’t throwing up a code?

I would appreciate any help.

Thanks!

It's worrying there's no air filter. That needs sorting asap. Get the fault codes sorted too. What's the oil consumption like? 

And any smoke out of the exhaust and if so what colour? 

When was the car last serviced? Including fuel filter. 

Are these any boost leaks I wonder? 

16mpg would be worse than a S3!