MK4 GTI 2.0 AQY MPG somehow getting worse & slight missfire!!

[Mike_MK4]

As the subject suggests, my MPG has been slowly getting worse after I've taken almost every step to fix things and make it better!
When I bought the car 7 months ago, i was getting 35-40 MPG on daily commute to work. Since then, I've had new cat, new front lambda sensor, new MAF, new thermostat and then i was start to get 25-30ish mpg.
I changed the ignition coil and plugs because i was still getting a slight missfire, Then I read posts on here and cleaned out the throttle body with carb cleaner and it somehow went down slightly further!

Any ideas on how i can git rid of the misfire and how i can get my MPG back up?
Thanks

[mar_k]

Mines the same, Used to get mid 30's but now lucky if it hits 30, These cars are not the best on fuel but shouldn't decrease as much.

Have you checked your Tyre air pressure as a few psi drop can make a massive difference, Maybe get the tracking checked aswell.

May well be the coolant temp sensor thats not working properly,
Have you had it connected to vagcom to see if any codes come up?

[Jonnybbad]

All cars will use more fuel this time of year as colder/denser air means more fuel is needed