1. Unichip
2. Small ECM Spacers (4)
3. Large kickplate Spacers (3)
4. Kickplate Bracket
5. Bolt for Kickplate Bracket
6. Auxiliary Boost Controller Assembly
7. 2mm Hex Key for Boost Controller 
8. Harness
9. Muffler
10. K&N Panel Filter

Recommended Tools List:

1. Long nose pliers
2. Wire cutters
3. WD-40
4. Flat head screw driver
5. Philips head screw driver
6. Socket Wrench
7. 10mm Socket
8. 12mm Socket (not shown)
9. 14mm Socket
10. Socket Wrench extension
11. 14mm open end wrench
12. 10mm open end wrench
13. Oxygen sensor wrench 

TurboXS Stage 4 Installation Instructions  

There are 12 basic steps to installing the full WRX Stage 4 Kit:

1. Remove the Factory Exhaust System (2 Hours)
2. Remove the Factory Turbocharger (1 Hour)
3. Install the TXS Cat-less Uppipe (2 Hours)
4. Install the Larger Fuel Pump (1 Hour)
5. Install the Larger Fuel Injectors (3 Hours)
6. Install the Turbocharger (1 Hour)
7. Install the TXS Turbo-back Exhaust (1 Hour)
8. Remove the Intake Resonator Chamber (45 Minutes)
9. Install the K&N Air Filter (10 Minutes)
10. Install the Auxiliary Boost Controller (10 Minutes)
11. Install the Unichip (20 Minutes)
12. Final Inspection and adjustments (1 Hour)

NOTE: It is best to do this step while the car is cool, as the muffler remains hot long after the car has stopped running.  

1. Jack the rear of the car up and place car jacks under each side of the car.
2. Use a 14mm socket wrench and 14mm box end wrench to remove the 2 bolts that hold the stock rear muffler assembly to the rear center pipe.  Retain bolts and gasket as you will re-use them to install the new muffler.
3. Spray a light lubricant (like WD-40) onto the 3 rubber muffler mounts and than remove the stock muffler from the mounts.  Be sure to support the muffler as you remove it from the mounts otherwise it will fall on you!  

NOTE:

1. It’s best to install the exhaust when the car and exhaust is cool.
2. Spray all bolts and exhaust hangers with WD-40 and let soak for a few minutes to ease the removal and installation process.
3. Exhaust installation is much easier with two sets of hands.  Get a friend to help you in exchange for letting them drive your WRX for a few minutes after the install is done!
4. Read the ENTIRE directions first as it will likely save you time!
5. Don’t even think of calling us if you have NOT read the directions yet!.  However, don’t hesitate to call us if you have read the directions but you still have questions or are having any problems.  Call us toll free at 877.887.2679.

Step 1:  Factory Exhaust Removal:

1. Remove the rear center section and rear muffler section as one piece by removing the spring bolts between the rear catalytic converter and the rear center section.  Retain the factory springs as you will re-use them when installing the TurboXS exhaust system.
2. Remove the intercooler by loosening the two bolts securing it to the mount.  Loosen the intercooler hoses from the throttle body and the turbocharger.  Remove the intercooler by gently pulling up and back.
3. Remove both intercooler brackets.
4. Remove the turbocharger upper heat shield (7, 10mm  bolts). See below.

5. Remove the turbocharger lower heat shield (3, 10mm bolts).  

6. Unbolt the downpipe from the turbocharger (5, 14mm nuts).
7. Disconnect the connector going to the rear oxygen sensor.
8. Push in or cut the plastic clip that holds the rear oxygen sensor to the crossmember.
9. Remove the bolt that holds the downpipe bracket to the transmission.
10. Remove the bolt that holds the catpipe to the hanger bracket.  Retain this bolt as it will be used when you install the TurboXS downpipe.
11. Remove the downpipe.
12. Remove the rear oxygen sensor from the downpipe.  Do not touch the sensor tip and keep it clean and free from contamination until it is re-installed.

1. Drain the coolant.  Remove the drain plug at the bottom of the radiator to drain the coolant and remove the coolant pressure cap.  
2. Remove the 2 rubber coolant lines.
3. Remove the hard oil line by unbolting the banjo connection on top of the turbo.  Be sure not to lose the 2 copper crush washers on both sides of the banjo joint.  
4. Remove the turbocharger.  Remove the 3, 14mm nuts securing the turbocharger to the uppipe.  You may have to slightly bend the hard oil line to remove the turbo.  Pull up on the turbocharger and slip the bottom rubber oil drain line off.  

1. Remove front plastic splash guard at the bottom of the engine bay by removing the 3, 1mm bolts and 3 plastic fasteners. 

2. Remove factory oxygen sensor located in the passenger side exhaust manifold.  Use of an 02 sensor wrench is highly recommend as to prevent damage to 02 sensor.  The 02 sensor can be accessed through a port located in the front passenger wheel well by removing the plastic fasteners and plastic cover.
3. Remove the factory heat shield on the passenger side exhaust manifold secured by 4, 12mm bolts.
4. Unbolt the factory uppipe from the exhaust manifold by removing the two 14mm bolts.  Save the gasket or replace with a new one.!
5. Remove the factory uppipe through the turbocharger area.
6. Install the supplied studs into TXS Uppipe.  Installing studs after inserting the TXS Uppipe may ease installation into the turbocharger bracket. 

7. Reinstall or replace the exhaust manifold gasket and bolt the TXS Uppipe onto the exhaust manifold.  If you opted to leave the studs out of the TXS Uppipe you must install those now.  It is critical that the TXS Uppipe is bolted and torqued to the exhaust manifold first to avoid an exhaust leak.

Step 4:  Install the Larger Fuel Pump

1. Remove the 3 plastic screws securing the passenger side carpeting against the floorboard and expose the factory ecu.  
2. Pull the plastic trim panel on the right side to expose the two electrical connectors shown below
3. Unplug the green connector shown below to disable the fuel pump.  
4. Start the engine and run until it stalls.  
5. Crank the engine over for 5 more seconds.

1. Remove the fuel pump assembly located under the rear seat back.  
2. Remove the rear seats in the sedan, and the trunk carpeting to expose the fuel pump cover (See Below). 
3. Remove the screws securing the fuel pump cover.  
4. Disconnect the white electrical connector on the fuel pump assembly and remove all fuel pump lines. 
5. Remove the screws securing the fuel pump assembly to the fuel tank and carefully lift the fuel pump assembly out of the fuel tank.

6. Remove the fuel pump from the in tank assembly.  
7. Disconnect the electrical connector, lift up on the rubber hose and pull the pump from it's rubber seat.  
8. Remove the locking washer and fuel strainer from your factory pump or use the supplied strainer and install it onto the replacement pump.  
9. Use a socket to evenly press on the lock washer.

10. Reinstall the fuel pump and assembly back into the car in the reverse order but do not reconnect the "green" connector in the first step of "Install the Larger Fuel Pump."

Drivers Side Injectors:

1. Remove "green" protective bracket from the fuel rail assembly by the 5 bolts.  This is a "PITA" but be patient and pull it out towards the rear of the car.
2. Remove 2, 12mm bolts between the injectors securing fuel rail to the heads and 1, 12mm bolt at the front of the fuel rail.
3. Disconnect electrical connectors from fuel injectors
4. Pull up on fuel rail and slip out injectors one at a time.  Be careful not to damage the fuel injector's rubber gaskets.
5. Install TXS Fuel Injectors in reverse of task "4." 
6. Put everything back together from "Install the Larger Fuel Injectors" in reverse order.

Passenger Side Injectors:

1. Remove the coolant assembly located next to the intake manifold.
2. Remove the various bolts securing hoses to the "green" bracket.
3. Remove "green" protective bracket from the fuel rail assembly by the 4  bolts.  This is a "PITA" but be patient.
4. Remove 2, 12mm bolts between the injectors securing fuel rail to the heads, 1, 12mm bolt at the front of the fuel rail and 2, 12mm bolts at the top of the fuel rail.
5. Disconnect electrical connectors from fuel injectors
6. Pull up on fuel rail and slip out injectors one at a time.  Be careful not to damage the fuel injector's rubber gaskets.
7. Install TXS Fuel Injectors in reverse of task "6." 
8. Put everything back together from "Install the Larger Fuel Injectors" in reverse order.

Double check Installation:

1. Make sure the all electrical connectors are installed to the fuel injectors.
2. Make sure electrical connectors are installed to the Tumble Generator Valves if removed during installation.
3. Make sure the fuel pressure regulator line is attached and secured.  If installed improperly, serious engine damage can occur as fuel pressure will not increase with boost.
4. Plug the green connector back in from "Depressurize the fuel system." 

1. Lower TXS Turbocharger onto the TXS Uppipe, ensuring that the oil drain line inserts fully into the rubber drain hose and spring clamp is in place.  If installed improperly, serious engine damage can occur if engine is starved of oil.
2. Reattach the rubber coolant lines and spring clamps.
3. Install the oil feed line making sure that a cooper washer is used on both sides of the banjo bolt.
4. Torque the TXS Turbocharger onto the TXS Uppipe with the 3, 14mm nuts.
5. Reinstall the coolant assembly hoses and spring clamps.

1. Install the TurboXS Downpipe to the turbocharger.  

2. Relocate the rubber drain tube exiting the firewall!  Remove the C clip with and move this to the adjacent hole 5" to the right.  This hole is difficult to see but you can feel it with your finger. 

3.    Now comes the hard part!  A.  Install the Cat-pipe to the downpipe.  Use the supplied Downpipe gasket between the Downpipe and the Cat-pipe.  Use the provided bolts, nuts and lock washers.  Install the provided Downpipe bracket to the top bolt of the downpipe-to-cat pipe flange.  B.  Secure the exhaust to the factory downpipe hanger bracket.  The supplied bracket may have to be bent slightly to get it to line up correctly with the factory hanger bracket.  (See Figure below).  Securing this bracket is a PITA, but is required to ensure that the exhaust does not move around during “spirited” driving.

4.    Install the donut gasket to the Cat-pipe.   Use the factory springs and place them on the outside of the midpipe flange.                              

5.    Install the rear oxygen sensor to the Cat-pipe which resides in a different location than on the O.E. exhaust.

NOTE:  If you have two people doing the installation, it is generally easier to do steps 1-4 above BEFORE installing the downpipe to the turbo.  However the two pipes together are very heavy and unwieldy if you are doing the installation by yourself.  

6.    Install the rear Mid-pipe to the Cat-pipe.  First hang the pipe on the factory hanger and than use the included bolts with sleeves and the original factory springs that were removed in 1. above to secure the Mid-pipe to the Cat-pipe.  See Figure Y.

7.    Install the rear muffler assembly re-using the original gasket and bolts.

8.    Re-connect the rear oxygen sensor to the wiring harness.  It will be necessary to create some “slack” in the front part of the oxygen sensor wiring harness in order to re-install it into the new location.  There are several zip ties affixing the wiring harness to the transmission.  Simply snip one or two of them in order to get enough slack in the line to allow you to reconnect the oxygen sensor.  Use some zip ties to re-secure the wiring harness. 

  Optional:

Using an angle grinder or dremel, trim the turbocharger upper heat shield to fit the TXS Downpipe and reinstall to turbocharger.  

Steps to Intake Resonator Chamber removal (refer to picture above):  

The intake resonator chamber is located inside the passenger side fender-well.  The resonator chamber is basically a muffler designed to reduce the intake noise.  However, it also restricts intake airflow.  Removing it will allow your turbo to “breathe” easier and should result in a slight performance gain.  A side benefit is that you will be able to hear the turbo spool-up better as well as the stock bypass valve when it goes off.

Note:  This step is optional, but is suggested because it frees up the WRX’s air intake system.  However, the car will be noticeably noisier as you will hear the turbo spool up, the engine rev, and the bypass valve go off.  If you are trying to keep the car “stock quiet”, we do not recommend doing this mod.

 1.    First, remove the air intake duct [1].  It is in the front on the passenger side and is a black plastic duct that runs from the front of the engine bay into the passenger side fender-well.  Use a 10mm socket wrench to remove the two bolts at the front of the air intake duct.

2.     Next, remove the air cleaner case [2].  Although the resonator chamber can be removed without taking out the air cleaner case, we find it was easier to do it with the air cleaner case out of the way and it only takes 5 minutes or so to remove it, so why not! 

a.                  Unclip the MAF sensor plug [3] and move to side

b.                  Pop out hoses and throttle cable from supports and move to side

c.                  Use a flat head screwdriver to loosen hose clamp closest to air cleaner case [2]

d.                  Unclip clips on air cleaner case [4]

e.                  Remove top of air cleaner case and air filter and put off to the side

f.                    Using a 12mm socket wrench with extension, remove the two (2) bolts holding the bottom of the air cleaner case in place

g.                  Remove the bottom of the air cleaner case from the car and place to the side

3.      In order to get access to the resonator chamber, you now need to jack up the front passenger side of the car and remove the front tire.  Use jack stands to support the car while you are working!

4.      Remove the plastic covers inside the wheel well by popping out all of the various fasteners holding them in place.  Be careful not to damage the fasteners as you pop them out.  We suggest you organize the fasteners as you take them off so you know what clip goes where when you re-install the covers (maybe duct tape them to the cover near the hole).

5.      Now you can finally remove the resonator chamber!  Use a 10mm crescent wrench to remove the two bolts holding the resonator chamber in place. One bolt is in the engine bay at the top of the resonator and the other is on the opposite side, underneath the resonator.  Be sure to remove grommets when removing the bolts so that you may replace the resonator chamber in the future if you desire.

6.      Replace wheel well covers and the tire and lower car back to the floor.

7.      Replace the air cleaner case [2] by reversing the steps in 2 above.  If you are replacing the air filter with the K&N panel filter, skip to Section 3 now, replace the filter and than come back when you are done.

8.      Replace the air intake duct [1].

9.       You can seal the air cleaner case [2] to the fender well with some hardware store adhesive backed weather stripping.  You can seal the air intake duct [1] to the fender well by wrapping the end in adhesive backed foam tape.

3. Unplug the stock wiring harness (5 connectors) Using a small screwdriver, push down on the top of the factory male connector at the bottom of the ECM.  Being careful, push/wiggle/lever the male connector out of the female receptacle.  It is not easy to do at first, but take your time and slowly work each of the 5 connectors out.  Start from the bottom connector and work your way up to the top connector.  It will get easier as you “get the feel” of unplugging them after you’ve successfully removed one or two plugs from the receptacle.

4. Mount the TurboXS Unichip harness over the stock ECM

          a.  Remove the four (4) Phillips head screws next to the plug receptacle from the stock ECM cover

         b.  Screw the four (4) thin hex head spacers into screw holes of the ECM case

          c.  Line up the mounting holes of the Unichip harness PCB to the spacers and secure the Unichip harness to the stock ECM      with the stock screws.

5. Plug in the five (5) plugs of the Unichip harness into the receptacles of the factory ECM.  Each plug will only fit in one (1) particular receptacle slot only, so you cannot get this part wrong.  Just take your time and make sure each plug “snaps” into place.  Inspect that all plugs are secured into the receptacle.
6. Plug the five (5) factory wiring harness plugs into the receptacle of the TurboXS Unichip harness.  Again, each plug will fit in one (1) particular receptacle slot only.  Be sure each plug “snaps” into place.
7. Plug the Unichip harness into the Unichip, peel off double sided tape on the back of the Unichip and secure the Unichip to the factory ECM.
8. Inspect that all plugs are secured into their receptacles.  The Unichip is now installed!

Before re-installing the kick-plate and carpet, it is a good idea to test that all connections are good and that everything is working as it should:  

9. Re-connect the negative lead of the battery terminal using a 10mm open-end wrench.  
10. Re-mount the factory ECM with the stock nuts.  
11. Screw in the three (3) kick-plate spacers into the mounting holes on the X-brace on the floor.  
12. Insert one of the kickplate bracket holes onto the top kickplate mounting stud and secure with the stock nut.  
13. Get the kickplate roughly positioned over the ECM, and insert the included bolt through the other hole, align the top kickplate hole, push bolt through hole and loosely tighten the bolt.   
14. Now align the other three kickplate holes to the spacers and screw the three 12mm bolts through the kickplate and into the spacers.  Now tighten all bolts and make sure the kick-plate is secure.

15. Re-install the carpet, doorsill and floor mat and the installation is complete.  
16. Please note that by having the battery terminal disconnected for a few minutes, you have cleared the ECUs memory of have “re-set the ECU”.  Therefore, the car may idle and run slight rough while it re-learns fuelling over the next two days or so.  The Unichip does not modify idle fuel or timing at all.   

1. Double check that all vacuum, boost, coolant, and vent hoses have been properly installed.
2. Double check the fuel lines and fuel pressure regulator boost/vacuum line.
3. Refill coolant and oil. See step 5  for details on bleeding coolant system of air.
4. Start the car.
5. Bleed the coolant system of air by removing the coolant pressure cap while car is still cold but running.  Add coolant until the reservoir is completely full.  Replace pressure cap.
6. Make sure there are no fuel, oil or coolant leaks.
7. Fuel pressure should be approximately 38psi after the idle settles.  If not double check your fuel component installation.
8. Short and long term fuel trims should be +- 10%.  If not please call TurboXS directly toll free at 877.887.2679 or e-mail us as tech@turboxs.com.  
9. Monitor check engine lights.  It is highly likely you'll get a P0420 CEL due to the removal of 2 catalytic converts.  This is normal but will not effect performance.  This is the only CEL you should get from this kit.  If you get others, follow the Subaru Service Manuals recommended steps to diagnose the cause.
10. If all goes well, continue with step 10.  If there are any problems, please call TurboXS directly toll free at 877.887.2679 or e-mail us as tech@turboxs.com.  
11. Take the car for a drive and when it is warmed up, check that the boost curve is as described in Section 4 (peak boost is achieved in 4^th gear).  It is normal with the Stages 4 kit to have to open the ABC 4-6 turns.
12. Make sure fuel pressure rises with boost.
13. Make sure car accelerates smoothly and feels powerful.
14. If you think anything is wrong, do not drive aggressively, and nurse it out of boost.  If you think the Unichip is the cause you can always unplug it and run your factory ecu.  This is the beauty of the plug & play harness! Please call TurboXS directly toll free at 877.887.2679 or e-mail us as tech@turboxs.com.  

Drive your WRX safely, responsibly and enjoy the new power!