The K&N 57-2553 is a complete cold air intake system for the 4.6L V8 in the Ford Crown Victoria. It centers on a rotationally molded high-density polyethylene intake tube, paired with an oversized conical filter that is washable and reusable. The manufacturer says the kit replaces the factory air filter and intake tube, so it fully swaps out the stock airbox assembly rather than adding a drop-in element.
The manufacturer's dyno chart lists an estimated gain of about 13 horsepower at 4979 RPM and roughly 13.8 lb-ft of torque, which is the core reason to choose it over the stock setup. Its oiled cotton filter media is designed for up to 100,000 miles between filter services under normal highway driving, so it avoids the recurring cost of disposable paper elements. Buyers should note the manufacturer states this kit is not legal for use on this vehicle in California, so check your state's emissions rules before buying. Crown Vic owners searching for a 2003 4.6 CAI, 57-2553 FIPK, or oiled cotton Crown Vic intake will find this kit's specifications below.
The manufacturer states that this kit is not legal for use on this vehicle in California. Confirm your state's emissions requirements before purchasing.
The filter is washable and reusable. The manufacturer indicates it can go up to 100,000 miles between cleanings under normal highway driving, but harsher conditions will shorten that interval. Owners on user forums report that oiled filters can foul the mass airflow sensor on these vehicles, so use only the amount of oil the manufacturer specifies and keep the filter from over-oiling.
The manufacturer lists this kit for the 2003 Ford Crown Victoria with the 4.6L V8. Confirm 2004 fitment directly with the manufacturer before ordering.
The manufacturer provides an installation instruction sheet with this kit, and the intake is designed to replace the factory tube and filter without custom fabrication. Owners on user forums report that the mass airflow sensor is the main sticking point: on the 2003 and 2004 models the intake air temperature sensor is integrated with the MAF, and some owners have needed to drill a hole in the airbox to accommodate the IAT sensor. Some owners also report that the MAF retaining screw uses a five-point head that standard hex keys will not fit, so bring the correct driver before you start. Plan for a careful, unhurried install and keep the MAF connector clean and undisturbed.
