Congratulations on your purchase of the COBB Tuning Fuel Pressure Regulator Kit for your 2008+ Subaru STI! The following instructions will assist you through your installation process. Please read them first BEFORE beginning the install and familiarize yourself with the steps and tools needed. If you feel that you cannot properly perform this installation, we HIGHLY recommend you take the vehicle to a qualified and experienced automotive technician. 

Part List

• 1 x Fuel Pressure Regulator

• 1 x Long Assembled Fuel Line (Feed/Upper Line)

• 1 x Medium Assembled Fuel Line (Return/Lower Line)

• 1 x Small Assembled Fuel Line (Return/Lower Line)

• 1 x Spacer

• 1 x M8x35 Flange bolt

• 1 x M8 Flange nut

• 2 x Fuel Injection Hose Clamps

• 6 x Small Zip Ties

• 1 x Manifold Reference Relocation "Tee"

• 1 x Small Black Vacuum Cap

• 1 x Section of 6mm black silicone hose (Tee to FPR line)

• 1 x Section of 4mm black silicone hose (Tee to BPV line)

Tools Needed

• 5/16" or 8mm Fuel Line Disconnect Tool (Available at Professional Tool Sources)

• 7mm Nut Driver 

• Flat Head Screw Driver

• 10mm Wrench

• 12mm Wrench

• 10mm Socket

• 12mm Socket

• Ratchet

• Pliers 

• Diagonal Cutters or Scissors (Hose Cutting tools suggested for straight cuts)

• Safety Glasses

• Rags

• Silicone Spray or Similar

Removal of Stock Fuel Lines

1. If possible, discharge the existing fuel pressure from the system.  One potential method is to disable the fuel pump by pulling the fuse on the driver’s side of the engine bay (consult the underside of the lid for correct fuse location), then attempt to start the vehicle. Consult the factory service manual for OEM methods. 
                                                               
   
   

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2. Disconnect the vehicle’s negative battery terminal with a 10mm wrench or socket. Ensure no alternate sources of spark or flame are present.
   
   
   

3.  Prepare spill catch rags in case of fuel spills during OEM line removal.
   
   
   

4. Remove the factory fuel lines and fuel pressure regulator (FPR) from the fuel rails and feed/return lines using 5/16" or 8mm quick-disconnect fuel line tool (I.E. AST #8028). Removal can be tricky, so please take your time. 
   When done properly, the connectors will easily slide off.
   
   
   

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5.  Remove the fuel line retainer from the metal bracket using a pair of pliers to pinch the tabs and push it through.

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      6. Remove the manifold pressure reference from the OEM FPR and remove the assembly from the engine bay. The factory FPR, dampers and hose assembly is no longer needed. Be careful as excess fuel may continue to

         drain from the assembly.