shaners90lxhatch

The only warranty issues you will deal with is if your filter let some foreign object into the engine, or if the filter is found to contaminate the sensor. The dealer may charge you for the repairs if that is the case (your filter that trashed the sensor). Now, this does not happen to everyone and the filter IS oiled too much out of the box. But aside from the oil factor, Ford tends to design the entire intake system around the MAF, so it is possible that any change to the system whatsoever could cause false fuel system codes (typically lean p0171,0174) including the filter itself. You can clean MAFs and if you had a customer pay job that is likely what they would do. The dealer will replace the sensor under warranty to prevent you coming back and cussing out the service advisor if the cleaning doesn't work. Honestly, if you keep an eye on residue in the system you have little or nothing to worry about. You do run the risk of setting codes and if you take it to the dealer, be prepared for them to argue that the aftermarket components play a factor. Even if they aren't, the guy feeding his family on book time for a stock vehicle doesn't want to monkey around your aftermarket stuff and potentially create more repair time that he won't get paid for. He would rather return it to stock and see if the codes come back. That way he can (hopefully) make the correct diagnosis and repairs the first time. It really is in your best interest to leave it but just understand the consequences of your actions. Worst case I see it; you are out the cost of a new MAF and the labor to install it. (if you accept the repairs of course).