Hi everyone new to the ecoboost forum, hoping someone can give me an answer. I put a Afe cold air intAke stage 2 dual filters on my 2012 ecoboost fx4 super crew. I definentally feel a slight increase in power and acceleration despite what people say about CAI's. But at low RPMs I hear a clunking sound if i press on and off on the pedal quick. I didn't notice it with the stock system. There is a slight bend at the end of one of the pipes where it meets the filter, but i made it work and it seems like everything is sealed good. Check it every other time i get home from work everything is tight still and it sounds good. Just wondering if anyone's experienced the same sound or if anyone knows what the weird low rpm clunking is. Sounds like it's definentally from the engine bay, not a drive shaft sound. Thanks guys