🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2004 Codes Chassis Code: GDB 👋 Introduction Market Position Segment: Performance Compact Sedan/Hatchback Positioning: Homologation special for WRC, rallying pedigree, enthusiast-focused performance model. Competitive Analysis Key Competitors: Mitsubishi Lancer Evolution, Ford Focus RS, Honda Civic Type R (where applicable). Key Features Performance Focus: Turbocharged boxer engine, Symmetrical All-Wheel Drive, advanced DCCD system, performance braking. Rally Heritage: Direct lineage to Subaru's World Rally Championship success, built for demanding conditions. 📋 Manual Details Coverage Areas Primary Coverage: Complete factory service and repair procedures for the 2004 Subaru Impreza WRX STI. Page Count Estimated Pages: 1500+ Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: Downloadable Digital Format (PDF) 📖 Manual Coverage Systems Covered Engine Mechanical: Detailed diagnosis, overhaul, and repair for the EJ207 engine (including turbocharger, intercooler, fuel injection, ignition, cooling systems). Transmission Drivetrain: Service and repair procedures for the 6-speed manual transmission (TY856), DCCD (Driver's Control Center Differential), center differential, rear differential, driveshafts, and axles. Brakes: Front Brembo 4-piston calipers, rear Brembo 2-piston calipers, ABS system diagnosis and repair, brake fluid specifications and bleeding procedures. Suspension Steering: Front MacPherson struts, rear multi-link suspension, power steering system diagnosis and repair, alignment specifications. Electrical Electronics: Full wiring diagrams, component locations, fuse box layouts, ECU pinouts, diagnostic trouble codes (DTCs), audio system, lighting, instrumentation, immobilizer system. Body Chassis: Body panel removal and installation, interior trim, glass, sunroof, body sealing, structural repair guidelines. Procedures Included Maintenance: Scheduled maintenance intervals, oil change procedures, filter replacement, spark plug replacement, coolant flushing, brake pad replacement. Troubleshooting: Extensive diagnostic procedures for all major systems, symptom-based troubleshooting guides, DTC interpretation and resolution. Repair Overhaul: Step-by-step instructions for engine rebuilds, transmission overhauls, suspension component replacement, brake system repairs, electrical component repair. Diagnostics: Procedures for using Subaru Select Monitor (SSM) or equivalent OBD-II scanners, data stream analysis, actuator testing. Technical Depth Depth: Comprehensive; covers everything from basic fluid checks to complete engine and transmission rebuilds, including detailed torque specifications and measurement tolerances. 📊 Manual Specifications File Format File Type: PDF Print Quality Quality: High-resolution, printable pages with clear diagrams and text. Binding Type Binding: N/A (Digital Download) Paper Type Paper: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Code: EJ207 Configuration: 2.0L Flat-4 (Boxer), DOHC, 16-valve Induction: Twin-scroll Turbocharger (IHI VF35 or similar), Top-mount Intercooler Performance Horsepower Ps: 265 PS (approx. 261 bhp) Torque Nm: 343 Nm (approx. 253 lb-ft) Fuel System Fuel Delivery: Sequential Electronic Fuel Injection (SEFI) Fuel Type: Unleaded Gasoline (Premium Unleaded 98 RON recommended) Other Engine Details Bore X Stroke: 92.0 mm x 75.0 mm Compression Ratio: 8.0:1 🔧 Transmission Standard Type: 6-speed Manual Transmission Transmission Code: TY856 Optional Transmission: None (STI was exclusively manual) Features Dccd: Driver's Control Center Differential (manual locking/auto modes) AWD System: Subaru Symmetrical All-Wheel Drive Fluid Specifications Gear Oil Type: API GL-5, SAE 75W-90 (Hypoid Gear Oil) 📐 Dimensions Exterior Length: 4,405 mm (173.4 in) Width: 1,770 mm (69.7 in) Height: 1,410 mm (55.5 in) Wheelbase: 2,510 mm (98.8 in) Weights Curb Weight: 1,440 kg (3,175 lbs) approx. Gross Vehicle Weight Rating: 1,840 kg (4,057 lbs) approx. Cargo Trunk Volume: 370 L (13.1 cu ft) approx. (Sedan) 🛡️ Safety Features Ratings NHTSA Front Impact: Not explicitly rated for 2004 model year in the same format as later years, but known for robust chassis design. Active Features ABS: Standard (with EBD - Electronic Brakeforce Distribution) Traction Control: Standard (SI-DRIVE not applicable) Passive Features Airbags: Driver and Passenger Frontal Airbags, Side Airbags (optional/market dependent) Body Structure: Ring-shaped reinforcement frame, energy-absorbing crumple zones. 💡 Technology Features Infotainment Head Unit: Factory single-DIN CD player with AM/FM radio; aftermarket upgrades common. Speakers: Factory 6-speaker system (door speakers, tweeters, rear coaxial). Driver Assistance Cruise Control: Standard Limited Slip Differential: Front Helical LSD, Rear Viscous LSD (in addition to DCCD). Connectivity Aux Input: Not standard; aftermarket solutions required. 🔧 Maintenance Service Intervals Oil Change: Every 7,500 miles or 6 months, whichever comes first (or more frequently under hard driving conditions). Air Filter: Every 15,000 miles or 12 months. Spark Plugs: Every 30,000 miles (iridium type). Timing Belt: Not applicable; EJ207 uses a timing chain system (though some components may require periodic inspection/replacement). Fluid Specifications Engine Oil Capacity: 4.5 Liters (4.8 US Quarts) with filter change (SAE 5W-30, API SG or SH, ILSAC GF-2 or higher recommended). Coolant Type: Subaru Super Coolant (Blue) or equivalent silicate-free, long-life coolant. Brake Fluid: DOT 3 or DOT 4. Known Issues Engine Wear: Piston ring land failure on heavily modified or poorly maintained engines; head gasket issues are less common than on other Subaru models but can occur. Turbocharger: Potential for oil starvation if maintenance is neglected, leading to turbo failure. Dccd: Potential for electronic or mechanical issues with the DCCD unit over time, often related to fluid contamination or...