🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Model Generation: Third Generation (GR/GV) Model Years Covered: 2006-2007 Codes Chassis Codes: GDB (for 2006-2007 models, specifically variations within this generation) 👋 Introduction Market Position Segment: Performance Compact Sedan/Hatchback (based on Impreza platform) Competitors 2006-2007: Mitsubishi Lancer Evolution, Subaru WRX (non-STI variants), Subaru Legacy GT, Honda Civic Si, Volkswagen GTI, Mazda Mazdaspeed3. Competitive Analysis Key Differentiators: Symmetrical All-Wheel Drive, turbocharged boxer engine, rally-bred heritage, Driver Controlled Center Differential (DCCD). Key Features Performance Focus: Designed for enthusiasts seeking high performance, handling, and all-weather capability. Durability And Reliability: While performance-oriented, the STI is built with robust components for demanding driving conditions. Manual Value Proposition: Provides in-depth technical knowledge for DIY enthusiasts and professional mechanics to maintain and repair the WRX STI efficiently. 📋 Manual Details Coverage Areas Primary Regions Covered: Global (factory specifications applicable to North American, European, and Japanese markets, with specific regional variations noted where applicable) Page Count Estimated Page Count: 1000+ (typical for comprehensive factory service manuals of this era) Manual Type Type: Factory Service Manual / Workshop Manual / Repair Manual Language Language: English Format Format: Digital Download (PDF) 📖 Manual Coverage Systems Covered Engine Mechanical: Complete engine overhaul, internal components (pistons, connecting rods, crankshaft, camshafts, valves), timing belt/chain, cylinder heads, lubrication system, cooling system. Engine Performance Tuning: ECU tuning principles, fuel injection control, ignition timing, turbocharger operation and diagnosis, intercooler system. Fuel System: Fuel pump, fuel injectors, fuel lines, fuel pressure regulator, evaporative emission control (EVAP) system. Exhaust System: Exhaust manifold, catalytic converter, mufflers, oxygen sensors, emissions controls. Transmission Manual: Clutch system, gear selection, internal transmission components, differential, driveshafts, maintenance and repair. Transmission Automatic: N/A (This manual specifically covers WRX STI manual transmissions) All Wheel Drive System: Center differential (Driver Controlled Center Differential - DCCD), viscous coupling, drivetrain components, maintenance and diagnosis. Suspension System: Front and rear struts, springs, control arms, bushings, sway bars, alignment specifications, and procedures. Steering System: Power steering pump, rack and pinion assembly, steering column, linkages, troubleshooting. Brake System: Brake calipers (including Brembo on STI), rotors, pads, ABS system, brake fluid specifications, bleeding procedures, parking brake. Electrical System: Battery, alternator, starter, wiring diagrams, fuses, relays, lighting systems, ignition system. Engine Control Module ECM: ECU functions, sensor inputs and outputs, diagnostic trouble codes (DTCs), sensor calibration, idle control. Body And Chassis: Body panel removal and installation, door mechanisms, glass, interior trim, chassis components, corrosion protection. HVAC System: Air conditioning system, heater core, blower motor, controls, refrigerant handling and charging. Safety Systems: Airbag system, seatbelts, SRS (Supplemental Restraint System) diagnosis and repair. Procedures Included Routine Maintenance: Oil and filter changes, fluid checks and top-offs, tire rotations, brake inspections, air filter replacement. Troubleshooting Diagnostics: Systematic diagnostic charts for common and uncommon issues, DTC interpretation, component testing procedures. Engine Repair: Complete engine rebuild procedures, head gasket replacement, piston ring installation, bearing replacement. Transmission Overhaul: Detailed steps for disassembling and reassembling the manual transmission, including gear replacement and synchro ring servicing. Suspension Replacement: Strut and shock absorber replacement, bushing renewal, steering component replacement. Brake Service: Pad and rotor replacement, caliper servicing, bleeding procedure for ABS-equipped vehicles. Electrical Diagnostics: Wiring harness troubleshooting, component testing using multimeters and oscilloscopes, power and ground testing. Turbocharger Maintenance: Inspection, lubrication, and potential repair/replacement procedures for the turbocharger unit. Dccd Adjustment And Repair: Procedures for diagnosing and potentially adjusting or repairing the Driver Controlled Center Differential system. Body Panel Repair: Guidelines for the removal, installation, and adjustment of body panels, doors, and trim. Technical Depth Depth: Comprehensive. Covers everything from basic maintenance to complete engine and transmission rebuilds, including electrical system diagnostics and bodywork. Diagnostic Tools: Details required diagnostic tools, scan tool protocols (OBD-II), and specialized Subaru diagnostic equipment. Torque Specifications: Exact torque values for all critical fasteners, critical for engine assembly, suspension, and chassis components. Clearances And Tolerances: Specifications for engine bearing clearances, piston ring gaps, valve lash, and other critical mechanical tolerances. Wiring Diagrams: Detailed, color-coded wiring diagrams for all electrical systems, including engine control, body electrical, and chassis electronics. Special Tools: Lists and descriptions of Subaru-specific special tools required for certain repair procedures. 📊 Manual Specifications File Format File Type: PDF Searchability: Text-searchable PDF for quick information retrieval. Print Quality Quality: High resolution, suitable for printing specific sections or the entire manual. Binding Type Binding: N/A (Digital Download) Paper Type Paper: N/A (Digital Download) Compatibility Device Compatibility: Compatible with computers, tablets, and smartphones via PDF reader applications. ⚙️ Engine Specifications Primary Engine Engine Code: EJ257 Engine Type: 2.5L DOHC 16-valve turbocharged flat-four (Boxer) Performance Horsepower: 300 hp @ 6000 rpm (approximate, varies slightly by market/spec) Torque: 300 lb-ft @ 4000 rpm (approximate, varies slightly by market/spec) Fuel System Fuel Delivery: Multi-point Fuel Injection (MPI) Turbocharger: IHI VF39 (or similar twin-scroll turbocharger) Intercooler: Top-mounted air-to-air intercooler Recommended Fuel Octane Rating: Premium Unleaded...