🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Model Code: GDB (Hatchback/Wagon), GGB (Sedan - for some markets, but typically GDB refers to the chassis for this generation) Model Generation: Third Generation (2002-2007, chassis code GDB/GGB), specifically covering the mid-cycle refresh Codes Chassis Code: GDB 👋 Introduction Market Position Positioning: The 2004-2005 Impreza WRX STI represents a pinnacle of rally-inspired performance in a production sedan, targeting enthusiasts and drivers seeking track-capable handling and potent turbocharged power. Competitive Analysis Competitors: Competed against performance variants of models like the Mitsubishi Lancer Evolution, Ford Focus RS, Volkswagen Golf R, and Audi S3 of the era. Key Features Performance Focus: Renowned for its symmetrical All-Wheel Drive system, turbocharged Boxer engine, and track-tuned suspension, offering exceptional grip and acceleration. Rally Heritage: Directly derived from Subaru's World Rally Championship (WRC) heritage, carrying the performance DNA of its motorsport counterparts. Manual Value Value Proposition: Provides official, dealer-level repair and maintenance information, empowering owners and independent shops to perform accurate and efficient servicing. 📋 Manual Details Coverage Areas Covered Years: 2004, 2005 Region Of Origin: Likely North American market based on WRX STI designation, but often includes global specifications. Page Count Estimated Page Count: 1500+ (Typical for comprehensive factory service manuals) Manual Type Type: Factory Service Manual (FSM) / Workshop Manual Language Language: English Format Format: Digital Download (PDF likely) 📖 Manual Coverage Systems Covered Engine: 2.5L Turbocharged EJ257 Boxer Engine (including timing, lubrication, cooling, fuel injection, ignition, emissions, and engine management) Transmission: 6-speed Manual Transmission (TZ1A3ZG6KA, TY757VW4AA, etc. - specific gearboxes may vary by market and trim) Drivetrain: All-Wheel Drive System (DCCD - Driver's Control Center Differential, center differential, front/rear differentials, driveshafts, axles) Suspension: Front MacPherson strut with lower control arm, Rear multi-link suspension, adjustable components (camber bolts, etc.) Brakes: Front 4-piston Brembo calipers with 325mm ventilated discs, Rear 2-piston Brembo calipers with 300mm ventilated discs, ABS, Brake booster, master cylinder Steering: Power-assisted rack and pinion steering system Electrical: Complete electrical schematics, Body Control Module (BCM), ECU, sensors, lighting, power windows, mirrors, HVAC controls, audio system, airbags Body And Trim: Exterior body panels, interior trim, bumpers, spoilers, doors, hood, trunk, glass HVAC: Heating, Ventilation, and Air Conditioning system operation and repair Fuel System: Fuel tank, fuel pump, fuel lines, fuel injectors, fuel pressure regulator Exhaust System: Manifold, catalytic converter, muffler, O2 sensors Procedures Included Maintenance: Oil changes, filter replacements, spark plug replacement, fluid flushes (coolant, brake, clutch, transmission, differential), belt inspection/replacement, battery maintenance Diagnostics: Troubleshooting guides for common issues, DTC (Diagnostic Trouble Code) interpretation, sensor testing, circuit testing Repair: Engine overhaul, transmission rebuild, brake component replacement, suspension component replacement, electrical component repair/replacement, body panel repair Disassembly And Assembly: Step-by-step instructions for removing and installing major components and sub-assemblies Specifications And Tolerances: Torque specifications, alignment data, gap measurements, fluid capacities Wiring Diagrams: Detailed electrical schematics for all vehicle systems Technical Depth Depth: Comprehensive (from basic maintenance to complete engine and transmission overhauls, including advanced diagnostics and electrical troubleshooting) 📊 Manual Specifications File Format Format Details: PDF (typically, search functionality, bookmarking, printable pages) Print Quality Quality Description: High-resolution, clear diagrams and text, comparable to original factory documentation Binding Type Binding Description: Not applicable for digital download, but original manuals were typically spiral-bound or perfect-bound. Paper Type Paper Description: Not applicable for digital download, but original manuals were printed on durable paper stock. ⚙️ Engine Specifications Primary Engine Engine Code: EJ257 Configuration: 2.5L (2457cc) turbocharged and intercooled DOHC 16-valve horizontally opposed (Boxer) four-cylinder engine Performance Horsepower: 300 hp @ 6000 rpm (SAE Net) Torque: 300 lb-ft @ 4000 rpm (SAE Net) Bore X Stroke: 99.5 mm x 79.0 mm Compression Ratio: 8.4:1 Fuel System Fuel Delivery: Multi-point fuel injection (MPI), Sequential electronic fuel injection (SEFI) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Engine Management ECU Type: Denso ECU (specific part number varies, e.g., 22611AG571 for certain configurations) Cooling System Coolant Capacity: Approx. 7.8 liters (16.4 US pints) Lubrication System Oil Capacity: 5.0 US quarts (4.7 liters) with filter change Oil Type Recommendation: 5W-30 Synthetic (meeting API SN or equivalent) 🔧 Transmission Standard Type: 6-speed Manual Transmission Optional Type: N/A for WRX STI models of this generation; manual was standard. Features Dccd: Driver's Control Center Differential (DCCD) with automatic and manual modes for torque distribution adjustment. Fluid Specs Transmission Fluid Type: Subaru Extra-S Gear Oil or equivalent GL-5 75W-90 Fluid Capacity Transmission Fluid Capacity: Approx. 3.4 liters (7.2 US pints) Differential Fluid Front Differential Fluid Type: GL-5 75W-90 Rear Differential Fluid Type: GL-5 75W-90 📐 Dimensions Exterior Wheelbase: 2629 mm (103.5 in) Length: 4405 mm (173.4 in) Width: 1795 mm (70.7 in) Height: 1445 mm (56.9 in) Front Track: 1530 mm (60.2 in) Rear Track: 1535 mm (60.4 in) Weights Curb Weight: Approx. 1475 kg (3252 lbs) Gross Vehicle Weight Rating: N/A (typically not a primary...