G'day all. New to the forums and looking for some help with an x-type 2.1 V6 I recently purchased.

Fuel consumption seems to be a little high. The best I can get is about 12.2L/100k's (23mpg).

Have checked for error codes, but nothing comes up.

Fuel also seems to drain back down into the tank when parked. I have a fairly steep driveway, and if parked facing up the driveway, car will stall when first started in the morning. Have to turn the key a few times to get the fuel back up before it will start. I assume there must be an air leak somewhere causing this? and this may also be contributing to the excess fuel consumption?
Where should I start looking for the problem.

Thanks for your help
Rob