🏷️ Basic Information Identification Make: Subaru Model: WRX STI Year: 2004 Generation Generation Code: GDB (2nd Generation, "Blobeye" revision) Codes Chassis Code: GDB Engine Code: EJ257 👋 Introduction Market Position Market Segment: Performance Sedan / Rally-Bred Sport Compact Target Audience: Enthusiasts, DIY mechanics, professional automotive technicians specializing in Subaru performance vehicles. Competitive Analysis Key Competitors 2004: Mitsubishi Lancer Evolution VIII, Ford Focus SVT, Volkswagen Golf GTI, Acura RSX Type-S. Key Features Vehicle Highlight 1: Symmetrical All-Wheel Drive (AWD) with DCCD. Vehicle Highlight 2: Legendary EJ257 Boxer Engine with Turbocharging. Vehicle Highlight 3: Performance-tuned suspension and braking systems. Manual Value Proposition Value To Owner: Enables owners to perform all maintenance and repairs, saving money and ensuring optimal performance. Value To Technician: Provides authoritative, factory-level information for efficient and accurate servicing. 📋 Manual Details Coverage Areas Coverage Scope: Complete service and repair coverage for all aspects of the 2004 Subaru WRX STI. Page Count Estimated Page Count: 1500+ Manual Type Manual Type: Workshop Service Repair Manual (WSRM) Language Language: English Format Format: Digital (Likely PDF, Print-On-Demand) 📖 Manual Coverage Systems Covered Engine Mechanical: Detailed breakdown of EJ257 engine: disassembly, assembly, cylinder head, block, crankshaft, pistons, connecting rods, lubrication, cooling systems. Engine Performance: Fuel injection system (ECU control, injectors, fuel pump, pressure regulator), ignition system, emissions control, turbocharger (assembly, wastegate, blow-off valve). Transmission Drivetrain: Manual transmission (TY856), clutch system, propeller shaft, front/rear differentials, DCCD (Driver's Control Centre Differential) system. Suspension Steering: Front and rear suspension (struts, control arms, stabilizer bars), power steering system, steering column. Brakes: Front and rear brake systems (calipers, rotors, pads), ABS (Anti-lock Braking System), brake hydraulics, parking brake. Electrical Systems: Wiring diagrams, power distribution, starting/charging system, lighting, instrumentation, body electronics, ECUs (Engine Control Unit, Transmission Control Unit, etc.). Body Chassis: Body panel removal/installation, interior trim, exterior trim, chassis components, corrosion protection. Procedures Included Maintenance: Routine maintenance schedules, oil changes, filter replacements, spark plug replacement, coolant service, brake fluid service. Repair Overhaul: Complete engine overhaul, transmission rebuild, suspension component replacement, brake caliper/rotor replacement, turbocharger service. Diagnostics: Troubleshooting guides, fault code interpretation, diagnostic procedures for various systems, use of Subaru Select Monitor (SSM). Specifications Data: Torque specifications, clearances, fluid capacities, technical data for all components. Technical Depth Depth: Comprehensive, from basic fluid checks to complete engine and transmission rebuilds, including ECU tuning parameter descriptions. 📊 Manual Specifications File Format File Format: PDF Searchable Text: Yes (Assumed for digital format) Print Quality Print Quality Recommendation: High-resolution for clear diagrams and text. Binding Type Binding Type: N/A (Digital), Professional binding recommended if printed. Paper Type Paper Type Recommendation: Durable, matte finish paper for workshop use if printed. ⚙️ Engine Specifications Primary Engine Engine Code: EJ257 Engine Type: 2.5L DOHC turbocharged flat-four boxer engine Performance Horsepower Hp: 260 hp @ 5600 rpm (USDM specification) Torque Lb Ft: 290 lb-ft @ 3600 rpm (USDM specification) Fuel System Fuel Delivery: Multi-point fuel injection (MPI), Sequential Electronic Fuel Injection (SEFI) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Induction Turbocharger: IHI VF39 Compression Ratio Compression Ratio: 8.2:1 🔧 Transmission Standard Transmission Type: 6-speed manual transmission Transmission Model: TY856 Optional Optional Transmission: N/A for WRX STI Features Dccd: Driver's Control Centre Differential (DCCD) with manual/auto modes Fluid Specifications Manual Transmission Fluid: Subaru Extra S Gear Oil (or equivalent API GL-5 75W-90) Clutch Clutch Type: Hydraulically operated, multi-plate, dry type 📐 Dimensions Exterior Wheelbase In: 104.0 Length In: 173.8 Width In: 69.7 Height In: 57.1 Weights Curb Weight Lbs: 3263 Wheels Tires Wheel Size: 17 x 7.5 inches Tire Size: 225/45R17 Bolt Pattern: 5x100mm 🛡️ Safety Features Ratings NHTSA Frontal Driver: 5-Star NHTSA Frontal Passenger: 5-Star IIHS Moderate Overlap Frontal: Good Active Features ABS: Yes, 4-wheel disc brakes with ABS Traction Control: Yes, Subaru's Symmetrical AWD system Passive Features Airbags: Frontal airbags, Front side-impact airbags Seatbelts: 3-point front and rear seatbelts with pretensioners 💡 Technology Features Infotainment Head Unit: Basic AM/FM/CD stereo system, optional CD changer. Analog climate controls. Driver Assistance Cruise Control: Standard electronic cruise control. Dccd: Electronically controlled center differential for torque distribution adjustment. Connectivity Auxiliary Input: Limited to aftermarket integrations; no standard USB or Bluetooth. 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 3 months (severe conditions) / 7,500 miles or 7.5 months (normal conditions) - Consult manual for specifics. Engine Air Filter Replacement: Every 15,000 miles or 15 months. Cabin Air Filter Replacement: Every 15,000 miles or 15 months. Spark Plug Replacement: Every 30,000 miles (NGK PFR7G recommended). Timing Belt Replacement: N/A - EJ257 uses a timing chain, not a belt. Fluid Specifications Engine Oil Capacity: 5.5 US quarts (with filter) of 5W-30 synthetic oil. Coolant Type: Subaru Super Coolant (Blue) or equivalent. Brake Fluid Type: DOT 3 or DOT 4 brake fluid. Known Issues Ring Land Failure: Common issue on EJ257 engines, particularly with aggressive tuning or poor fueling....