what year is your car? I'm not sure why that would happen, but I generally use only german stuff on my car. Right now, I have a K&N because you never have to replace them, and they're better flowing, but if you want to get a cheaper throw-away filter, Mahle and Mann are good german makes. I use their oil filters, I think one or both have air filters, worth checking out. I still don't think changing the air filter would mess something up like that, maybe you bumped something while you were in there or something. Sorry I can't help.