Probably the original

While the car was in the garage getting exhaust work done, I figured why not change the fuel filter as well?  While I was at it, I ripped apart the old one to check it's dirtiness -- turns out it was plenty dirty, but I'm not sure if a clean filter will make a difference in the overall operation of the car.

As the filter does its job, what it catches will reduce the flow rate through the filter, meaning the pump will need to work harder to provide same amount of fuel as a clean filter, or the car will have figure out how to run with less gas that expected; in practice, both are probably happening.

Location and Removal

• 9mm socket or flathead screwdriver
• Quick release tool
• Basin to catch any fuel in the system
• Motorcraft FG986B filter (got mine from Amazon)

Fuel relay location

I didn't bother to run the system out of fuel (thus de-pressuring the fuel lines) by removing the fuel pump relay and cranking the engine.  If you want to go that route, here's the battery junction box with the relay circled.  Remove the relay and turn over the engine.  When it stops running (or after a few cranks with no start), the fuel pressure will be very low in the system and not much gasoline will splash on you when removing quick release.  For my car, the front-end was raised for about two weeks, so I figured that would be enough to result in low fuel pressure.

Fresh from HF

Quick Release

Pushed the new part in the clamp, making sure the flow arrow pointed away from the tank.  With a click, I fastened the connectors and tightened the clamp with a few twists.  A few cranks of the engine and it started.  No leaks! We'll call this done.

How dirty was it?

Looking at the outside of the canister doesn't tell one much about the state of the filter, the interesting part's on the inside. Let's dissect the old filter like a middle-school frog and see what it trapped over the years.  I was tempted to use my handy Dremel, but figured sparks and gasoline fumes would result in some unwanted outcomes.  So I made an initial cut with a hack saw and used metal shears for the test, working my way slowly around the can.

I have a picture of the filter, showing the feed side next to the filtrate side, where the feed side is on the bottom and the browner, dirtier filter side is on the top.  For those asleep during chemistry: there's three things in a filter system:

1. Feed, what goes through the filter. In this case the gas from the tank
2. Filtrate, what remains after passing through the filter.  In our example, cleaner fuel
3. Residue, what the filter catches and what we can see in our illustration.  Looks like the filter paper itself has a red tint and the feed side looks covered in a greyish haze compared to the more vivid filtrate side. 

Juat a few taps...

I let the filter paper dry overnight. With a little tapping, a nice pile of residue willingly fell out of the filter.  Some of this detritus might have been the paper disturbed when disassembling the filter, but the finer material is certainly residue. Without a basis for comparison, it's hard to tell how clogged the filter is compared to a new one and how the residue interferes with the flow through the medium and thus how much harder the fuel pump needs to work to compensate.  A more constrained fuel flow should result in a less-efficient engine as well, translating into lower fuel efficiency.  We'll see how the gas mileage changes over the next few tanks.