High fuel consumption since fitting k n air filter

My 2001 td5 seems to have vastly decreased since I fitted a panel k n air filter is this normal ?
It has the egr bypass and decat down pipe fitted but since fitting the k n air filter I've done 149 miles and it's used over half a tank !
Does the cars ecu need time to get used to the increased air flow is some thing wrong the old air filter was very dirty
Cheers


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I am here: http://maps.google.com/maps?ll=53.441091,-0.844029

It's possible that the oil they use on the k&n filters to help trap dust is coating your airflow meter and giving the ecu the wrong info regarding air flow

The idea of a K&N is improve performance by allowing more air into the engine and with the engine ecu adjusting the fuel air ratio automatically so better performance.
No changing jets in carbs any more as we use to do when K&Ns were fitted.

Better performance = higher fuel consumption, so now sort out the extraction side and you may get that extra performance, if such a thing can happen with a standard td5. But at the moment it's just the higer fuel consumption.