Low Mpg...Engine Management Light and Throttle Body

[warnesey333]

So I changed my sparks yesterday and since then the engine management light has been popping on saying I need to clean the throttle body.

Ok fair enough - I will get that done.

The one thing that has me concerned is the mpg has dropped to under 20 in the low gears (not raggin it - maybe 3k - 4k)
Normally it was at around 25 under these conditions and today I saw 11.

Now is this because the engine management light was on? Or could it be something else?

Any suggestions are greatly appreciated,

Jack

[warnesey333]

Well - cleaned Throttle body - was quite dirty but not extremely. MPG seems to be around 19 in 2nd just nipping around the block. Going to be doing about 14 mile in 10 mins so im going to see what my avg mpg is.

Hopefully everything is sorted!