🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2004 Codes Chassis Code: GDB Engine Code: EJ257 👋 Introduction Market Position Positioning: Performance compact sedan, rallying heritage, enthusiast-focused vehicle Competitive Analysis Competitors: Mitsubishi Lancer Evolution, Honda Civic Type R, Volkswagen Golf GTI Key Features Performance Features: Symmetrical All-Wheel Drive, turbocharged Boxer engine, performance-tuned suspension Rally Heritage: Direct lineage from WRC-winning vehicles 📋 Manual Details Coverage Areas Coverage: Complete vehicle coverage for the 2004 Subaru Impreza WRX STI Page Count Page Count: Estimated 2000+ pages (typical for full workshop manuals) Manual Type Type: Factory Service Manual / Workshop Manual / Repair Manual Language Language: English Format Format: Digital Download (PDF) 📖 Manual Coverage Systems Covered Powertrain: Engine (EJ257), transmission (6-speed manual), drivetrain (AWD system), exhaust system Chassis: Suspension (front/rear), steering system, braking system (ABS), wheels and tires Electrical: Wiring diagrams, engine control module (ECM), body control module (BCM), lighting, audio system, power accessories Body And Interior: Body panels, interior trim, seats, HVAC system, safety restraints (airbags) Procedures Included Maintenance: Scheduled maintenance, fluid changes, filter replacements, belt inspections Repair: Engine overhauls, transmission rebuilds, suspension component replacement, brake system repairs, electrical component diagnosis and replacement Diagnostics: Troubleshooting guides, diagnostic trouble codes (DTCs) interpretation, symptom-based diagnostics Specifications: Torque specifications, clearances, alignment data, electrical resistance values Technical Depth Depth: Comprehensive factory-level detail, suitable for professional technicians and experienced DIY enthusiasts 📊 Manual Specifications File Format PDF Quality: High-resolution, searchable text, printable pages Searchability: Fully searchable text for quick information retrieval Print Quality Print Recommendation: Optimized for printing individual sections or the entire manual Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally-opposed (Boxer), turbocharged, intercooled, DOHC, 16-valve Displacement: 2457 cc (2.5 Liters) Performance Horsepower: 300 hp @ 6000 rpm Torque: 300 lb-ft @ 4000 rpm Fuel System Fuel Delivery: Multi-point fuel injection (MPI), electronic throttle control Recommended Fuel: Premium Unleaded (91 octane or higher) Engine Management ECU Type: Denso ECU 🔧 Transmission Standard Transmission Type: 6-speed manual transmission Optional Optional Transmissions: None for STI model Features AWD System: Subaru Symmetrical All-Wheel Drive with Driver Controlled Center Differential (DCCD) Differential Types: Helical limited-slip front differential, viscous coupling limited-slip center differential, Helical limited-slip rear differential 📐 Dimensions Exterior Length: 173.8 inches Width: 69.7 inches Height: 57.7 inches Wheelbase: 100.5 inches Ground Clearance: 5.1 inches Weights Curb Weight: 3263 lbs 🛡️ Safety Features Ratings NHTSA Front Impact: 5-star driver, 5-star passenger IIHS Side Impact: Acceptable Active Features Braking System: 4-wheel disc brakes with ABS (Anti-lock Braking System), Front: 12.7-inch vented rotors with 4-piston Brembo calipers, Rear: 11.3-inch vented rotors with 2-piston Brembo calipers Traction Control: Standard (integrated with AWD and DCCD) Passive Features Airbags: Driver and front passenger airbags, front side-impact airbags Seatbelts: 3-point height-adjustable front seatbelts with pretensioners, LATCH child seat anchors 💡 Technology Features Infotainment Head Unit: Standard AM/FM/CD player with optional premium audio system Display: Basic LCD display for audio and clock functions Driver Assistance ABS: Standard Anti-lock Braking System AWD Control: Driver Controlled Center Differential (DCCD) for adjustable torque split Connectivity Auxiliary Input: Optional auxiliary audio input jack 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 3 months Air Filter Replacement: Every 15,000 miles or 12 months Spark Plug Replacement: Iridium: 60,000 miles Timing Belt Replacement: N/A (EJ257 uses a timing chain) Fluid Specifications Engine Oil Type: SAE 5W-30 Synthetic Engine Oil Capacity: 4.8 US quarts (4.5 liters) with filter Transmission Fluid Type: GL-4/GL-5 SAE 75W-90 Synthetic Differential Fluid Type: GL-5 SAE 75W-90 Synthetic (Front & Rear) Coolant Type: Subaru Super Coolant (Blue) or equivalent HOAT Known Issues Head Gasket Failure: Less common on EJ257 compared to earlier EJ25, but still a potential concern; proper maintenance is crucial. Piston Ringland Failure: Can occur with aggressive tuning or detonation; careful fuel selection and monitoring are important. Clutch Wear: High-performance nature can lead to faster clutch wear under spirited driving conditions. 📚 Vehicle History Brand Heritage Subaru Rally History: Long and successful history in World Rally Championship (WRC) with Impreza models Model Evolution Third Generation Gdb: Introduction of the wider body, improved chassis rigidity, and updated powertrain for the GDB generation (2002-2007) Production Production Years: 2002-2007 (GDB generation) Manufacturing Location: Japan 🏆 Awards & Recognition Recognitions Performance Awards: Consistently lauded by automotive press for its rally-bred performance and handling capabilities.