3" custom short ram

well....today we wasted quite some time building a 3 inch short ram for a 2004. we used a 3 inch 45° bend connected to a 5 inch section of 3" straight pipe and a 2" to 3" coupling. on the end we used a K&N filter. we drilled the holes for the MAF and vacuum hose. we set everything up. we turned on the car, it worked for 4 seconds, then it died. we tried again, and the same. we installed the stock intake and it worked once again. our theory: the car was running way too lean. if anybody else has any better ideas...i'd like to hear it

follow up: someone told me that maybe we put the MAF sensor too close to the filter, and it was reading too much air and shutting down. any mechanic here wanna back that up?