Replace The Fuel Filter on a 2005 Impreza WRX STI

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The 2004-2006 Subaru Impreza WRX STI's fuel filter is located in the fuel tank. It's supposed to last the life of your car, but as with all filters, it can get clogged up in rare cases.

The OEM filter costs more than the typical fuel filter and is a little more difficult to replace. If you're thinking of replacing yours, it may be wise to bypass the in-tank filter and install a canister style filter from a 02-04 WRX. The bracket and the filter mount on the driver's side strut tower.

My car is still super stock, so I kept with the OEM filter.

Subaru lists this filter for various Foresters and Impreza between 2004 and 2008. Make sure you check fitment to see if your model uses this filter.

  • 8mm, 10mm, 12mm sockets and a wrench
  • Phillips head screwdriver
  • Pliars
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Remove the Rear Seats


Make sure you position your car to get plenty of fresh air flow.

Park the car in a well ventilated area and roll down all the windows.

It'll help if you can also pop your trunk open.


Disconnect the battery.

Fuel + sparks = ambulance ride and skin grafts.


Follow steps 1-4 from Replacing Struts on a STI to remove the rear seat back and base.


Remove the vertical rear seat support bars (4 x 12mm bolts each) and plastic trunk separator.


Remove the fuel pump cover. It uses 4 Phillips head screws.


Disconnect the fuel pump electrical connector


Disconnect the 3 fuel hoses.

One is a quick disconnect and the other two are just barbed slip on tubes. The slip-on rubber hoses were difficult to slide off.

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Clean dirt off the top of the cover and surrounding area.


Remove the 8 10mm nuts on the fuel pump cover.


Lift the fuel pump assembly out of the tank.

The hoses will get in the way, just tuck them back when you can.

It is a very tight fit. You'll need to go slowly, turn, and twist it to get it out.

Be very careful not to bend, scrape, or bind any wires or parts of the fuel level sensor.

I was only able to get mine half way out before I continued to step 11.

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Remove the fuel level sensor bracket from the pump housing. It's bolted onto the back of the housing with a single 8mm nut.

Be extra careful to not drop the nut or the bracket into the tank.

I'm not absolutely positive you need to remove the level sensor bracket to get the pump out, but it seemed to help me.


With that disconnected, I was able to maneuver the pump out of the tank.

The large black rubber baffle attached to the bottom will squish down to allow you to remove it.


Optionally, now that the pump housing is out of the car, remove and replace the rubber gasket.

Take care to not get any extra dirt or grime into the tank.


Remove the Phillips head screw holding filter to the fuel pump housing.

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Disconnect the top of the fuel filter.

Gently angle the bottom of the fuel filter out, away from the housing. When it's far enough away, the top will be able to slide off the nipple.


Unclamp the lower hose fitting on the filter and remove the old fuel filter.

It will drain a bunch of fuel once it's disconnected, so just direct that into the tank.

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Move the ribbed silicone adapter from the old filter to the new one.

This little insert goes in the plastic top of the filter.


Mount the new filter by sliding the bottom into the hose, then angling the top into the nipple on the fuel pump housing.

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Replace the clamp on the lower part of the fuel filter.


Replace the Phillips head screw holding the filter to the housing.


Slide the pump housing back into the tank.

If you removed the level sensor like I did, it's time to re-connect it too. I did this the same way I removed it, by sliding the pump housing half way back in, then bolt the sensor bracket back onto the pump bracket.


Re-install the pump cover nuts.

Note that there are little rubber fingers that stick up from the gasket through holes in the cover. Line those up if you can.


Re install the hoses, clamps, and electrical connectors

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Test the fuel pump.

  1. Reconnect the battery
  2. prime the pump once or twice
  3. Check for leaks
  4. Start the car and make sure it runs
  5. Check dash for fuel level and any new warning lights.

Install the pump cover with 4 Phillips head screws.


Install the plastic trunk separator panel


Install the seat back bars.

There are 4 x 12mm bolts on each bar.


Install the seat backs.

The top hooks in by putting the seat in place and sliding down.

Install the 3 x 12mm bolts that hold it in place.


Install the seat bottoms. There are 2 x 12mm bolts securing the bottoms.

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