🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STi Year: 2004 Codes Chassis Code: GDB Engine Code: EJ257 👋 Introduction Market Position Positioning: The 2004 Subaru Impreza WRX STi (GDB generation) was positioned as a high-performance, rally-bred compact sports sedan, competing with vehicles like the Mitsubishi Lancer Evolution and the Volkswagen Golf GTI. It represented Subaru's commitment to performance tuning and motorsports heritage. Competitive Analysis Competitors: Mitsubishi Lancer Evolution VIII, Volkswagen Golf R32, Ford Focus RS (Mk1), Audi S3 (8L). Key Features Features: Symmetrical All-Wheel Drive, turbocharged EJ257 boxer engine, front LSD, DCCD (Driver Controlled Center Differential), Brembo brakes, aggressive aerodynamic styling, performance-tuned suspension. 📋 Manual Details Coverage Areas Systems Covered: General Information, Special Tools, Specifications, Maintenance, Engine Mechanical, Fuel System, Emission Control System, Engine Control System, Cooling System, Lubrication System, Turbocharger System, Transaxle (Manual), Drivetrain, Steering System, Suspension System, Brake System, Body, Exterior, Interior, HVAC (Heater and Air Conditioner), Electrical System, Wiring Diagrams, Troubleshooting, Diagnostics Page Count Estimated Page Count: Over 1500 pages (typical for a full factory service manual of this era) Manual Type Type: Factory Service Manual / Workshop Manual Language Language: English Format Format: Digital Download (PDF) 📖 Manual Coverage Systems Covered Engine Mechanical: Detailed procedures for engine assembly, disassembly, cylinder head, piston, crankshaft, connecting rods, timing belt, valve train, oil pump, oil pan, and turbocharger overhaul. Fuel And Emissions: Fuel injection system (DENSO), fuel pump, fuel injectors, fuel pressure regulator, EVAP system, catalytic converter, oxygen sensors, and emissions control components. Transaxle: Detailed procedures for the Subaru 6-speed manual transmission (TY856WB1AA/XA), including clutch, gearbox assembly, disassembly, bearing replacement, and gear synchronizer overhaul. Steering And Suspension: Front and rear suspension components, steering rack, power steering system, alignment specifications, shock absorbers, springs, control arms, and wheel bearings. Brakes: Front and rear brake systems (including Brembo 4-piston front calipers and 2-piston rear calipers), ABS system, brake fluid specifications, rotor and pad replacement, brake line bleeding, and master cylinder. Electrical System: Complete wiring diagrams for all vehicle systems, starter, alternator, battery, lighting, ignition, instrument cluster, ECU pinouts, and diagnostic connectors (OBD-II). Procedures Included Maintenance: Oil changes, filter replacements, spark plug replacement, coolant flushes, brake fluid changes, differential fluid changes, gearbox oil changes, and general inspections. Repair And Overhaul: Engine rebuilds, turbocharger replacement, transmission rebuilds, clutch replacement, suspension component replacement, brake caliper overhaul, and body panel repair. Diagnostics And Troubleshooting: Systematic troubleshooting guides for common and uncommon problems, diagnostic trouble codes (DTCs), and procedures for using diagnostic tools. Technical Depth Depth: Comprehensive, covering everything from basic maintenance to full engine and transmission rebuilds, including detailed diagnostic procedures and torque specifications. 📊 Manual Specifications File Format File Format: PDF Print Quality Quality: High-resolution, printable pages with clear diagrams and text. Binding Type Binding: Not applicable (Digital Download) Paper Type Paper Type: Not applicable (Digital Download) ⚙️ Engine Specifications Primary Engine Engine: 2.5L DOHC turbocharged Subaru Boxer engine Performance Horsepower: 300 hp @ 6000 rpm (JDM spec) Torque: 290 lb-ft @ 4000 rpm (JDM spec) Fuel System Injection Type: Sequential Electronic Fuel Injection (DENSO) Cooling System Coolant Type: Subaru Super Coolant (Blue) or equivalent ethylene glycol-based coolant with silicate inhibitors. Capacity: 7.0 L (7.4 US qt). Lubrication System Oil Capacity: 4.5 L (4.8 US qt) with filter change. Recommended oil: 5W-30 or 5W-40 synthetic. Turbocharger Turbocharger Model: IHI VF37 (variable geometry turbocharger) 🔧 Transmission Standard Transmission Type: 6-speed Manual Transaxle (TY856WB1AA/XA) Features Dccd: Driver Controlled Center Differential (DCCD) for manual adjustment of front/rear torque split. Fluid Specifications Gearbox Oil Type: Subaru Extra-S Gear Oil (API GL-5, SAE 75W-90) or equivalent. Capacity: 3.0 L (3.2 US qt). Front Differential Oil Type: API GL-5, SAE 80W-90. Capacity: 1.0 L (1.1 US qt). Rear Differential Oil Type: API GL-5, SAE 80W-90 (Viscous LSD). Capacity: 1.3 L (1.4 US qt). 📐 Dimensions Exterior Wheelbase: 2525 mm (99.4 inches) Length: 4415 mm (173.8 inches) Width: 1770 mm (69.7 inches) Height: 1400 mm (55.1 inches) Weights Curb Weight: 1460 kg (3219 lbs) - JDM Spec Wheels And Tires Wheel Bolt Pattern: 5x100mm Standard Tire Size: 225/45R17 Standard Wheel Size: 17x8JJ 🛡️ Safety Features Ratings NHTSA Front Crash Test: Not rated by NHTSA for this specific model year/trim in all markets. Generally considered a safe vehicle for its class. Active Features ABS: Standard Anti-lock Braking System (ABS) AWD: Standard Symmetrical All-Wheel Drive Passive Features Airbags: Front airbags, available side airbags. Body Structure: Reinforced body structure with crumple zones. 💡 Technology Features Infotainment Audio System: Factory AM/FM/CD stereo system with optional premium speakers. Basic controls, no advanced connectivity. Driver Assistance Cruise Control: Standard cruise control system. Climate Control HVAC System: Manual or automatic climate control system, depending on trim. Includes air conditioning, heater, and recirculation modes. 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 6 months, whichever comes first. For hard driving or track use, more frequent...