So, following the instructions from one of the users in this forum i did this little number DIY intake. it was fairly easy. Just follow the instructions in this link:
http://www.scionxdforum.com/forum/showthread.php?t=906
I dont know how to reset the MPG clock thou it went craxy. It went all the way down to 9MPG on saturday. I barely used my car on the weekend so today Monday its on 24 MPG and going up lil by lil. The same happend when i only change the air filter, it took up to 4 days to reach the expected MPG. I dont know if this is a usual behavior. Let me know.