Im not sure how bad this is but after looking at this site http://members.aol.com/solomiata/FE3.html and more to the point this picture http://members.aol.com/solomiata2/Sportagegasketmatch.jpg of the Kia intake manifold, there could be a bad match from the intake runners to the head. This is only a pic of the intake with the gasket on it. But if the gasket matches to the head then thats a VERY bad match and could effect both the power and economy?

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Pajero iO - Lift and 33s on the way smile