i put mine back in just to be safe...i have read a couple of reports proving that it runs way too lean if its removed. I try to be on the safe side....

 

My opinion : You will NOT run WAY to lean by adding the MMR intake or the HC trap. Yes, it is slightly leaner - but the car runs so rich to begin with - you will not cause any problems. I can account for this by taking it out and dynoing the car and checking the A/F ratio.

Now, if you dont want to remove it beaucse of your warrantty, I understand that. But don't think that it is giong to lean out your A/F to the point of causeing some type of damage.

 

The way I have understood it, is that is does not void the warranty.

However, it has the potential to have a warranty claim denied. Only if the warranty claim is the result of the change. If the warranty claim is not the result of the change, then Ford must fix it under the normal warranty rules. And there must be proof provided that the problem was casued by the modification.