05 STI running cobb stage 2 tune. The car has been running the K&N Typhoon intake since brand new but recently I stripped one of the MAF screw holes. The car has been idling at about 1100 rpm and not steady. I decided to just swap for a cobb intake as I figured it would match the tune better anyway. I unhooked the battery, did the swap and drove the car for about 15 minutes. My DAM was .125 the whole time and while at about half throttle, the car would stutter and I noticed the AFRs were hitting 18. Under full throttle, it would go back down to 12. Is the ECU still learning or is it possible my MAF is messed up? I cleaned it while I had it out but I guess I could have damaged it.