has any body had any problems with the amzoil air filter? i think i have traced hesitation problem between 3400 and 4000 rpm(feels like the ecu is pulling timing there) to the filter . iam going to put the stock filter back in again and see if itsmooths out one more time. i also have the gasket in the 'big air box' so i have experiment there as well. hopefully some one out there can save me a lot of time and tell what will work the bestin my99s????