Can anyone tell me what this filter is next to my air filter. All it says is what you see. There is a small tag on the side but it's too faded to read. Just trying to figure out what it is.

 

That's the charcoal canister

 

Ha! I think you're right Chris. It's been a while since I've had my '03 with the 5.4L. And mine still had the airbox, so I remember it different. I had a K&N in it, but just a stock box drop in. Looks like someone stuck the K&N filter sticker on the charcoal can. Funny!

That was the best truck I ever had. It even looks like the same color as mine. I sold it to a guy down the street with 125K on it, and he pulled his camper with it for another couple of years until someone creamed him and totaled the truck. That truck never saw a dealer the entire time I had it. Normal wear and tear replacement items is all it ever had (tires, battery, brakes, etc.). What a solid truck.

 

Looks like that filter could stand to be cleaned.

 

Gotta love when they take out the factory cold air intake to put in a POS K&N that sucks in nice hot under the hood air..

 

So if it's a charcoal filter what the hell is its purpose. And FYI I bought the truck with the aftermarket intake already on it. Another funny story when I had the exhaust changed out the guy told me it was a diesel performance exhaust that was on there. Don't ask me why

 

I've had that same POS CAI on my '03 5.4 for nearly a decade. No engine problems confirmed close to two years ago with a complete compression test. Never had intake issues whatsoever on the truck and have never bought an air filter for it. FWIW.

 

Let me google that for you

 

I pulled this from another members thread, I thought it was a pretty good explanation.




When the engine is running, during the purge cycle, the fuel vapor is purged from the canister and burned in the engine. The purge portion of the system consists of a canister purge valve, or solenoid, and utilizes the small port on the PCV valve.

When fuel is consumed from the tanks, fresh air enters the system, through the bottom of the charcoal canister, venting the tanks. The Activated charcoal in the canister acts as a filter. Allows fresh air to enter the system for venting, but traps fuel vapor inside the canister from escaping to the atmosphere.

Benefits of the system...

1: Your truck wont smell of gasoline on hot days parked in the sun.
2: Helps to keep fuel in your tank from evaporating.