🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX & STI Model Variant: GD/GG Chassis Model Year: 2004 Codes Chassis Code: GD (Sedan) / GG (Wagon) Engine Code Wrx: EJ205 Engine Code Sti: EJ257 👋 Introduction Market Position Vehicle Type: Compact Sports Sedan / Hatchback Target Audience: Enthusiast drivers, performance car buyers, rally racing fans Competitive Segment: Performance compacts, rallying-inspired homologation specials Competitive Analysis Key Competitors: Mitsubishi Lancer Evolution, Ford Focus RS, Honda Civic Type R (in later generations) Key Features Drivetrain: Symmetrical All-Wheel Drive (AWD) with front and rear limited-slip differentials (STI) or viscous center differential (WRX) Engine Philosophy: Turbocharged Boxer engines known for their low center of gravity and unique sound Rally Heritage: Direct lineage to Subaru's dominant World Rally Championship (WRC) cars 📋 Manual Details Coverage Areas Manual Type: Factory Service Repair Workshop Manual Language: English Format: Digital (PDF) Page Count Estimated Page Count: Approx. 2000+ pages (combining WRX and STI specific sections) Manual Type Digital Features: Searchable text, printable pages, high-resolution diagrams 📖 Manual Coverage Systems Covered Engine Mechanical: Engine assembly, disassembly, cylinder head, crankshaft, pistons, connecting rods, timing belt, lubrication system, cooling system, fuel injection, ignition system, turbocharger system Engine Control: ECU (Engine Control Unit) diagnosis, sensors, actuators, emission controls, evaporative emission control system (EVAP) Transmission Manual: Clutch system, 5-speed manual transmission (WRX), 6-speed manual transmission (STI), gearbox overhaul, gear ratios, shift linkage Transmission AWD: All-Wheel Drive system (AWD), viscous center differential, rear differential, front differential, power transfer unit (PTU), viscous coupling unit (VCU) Suspension: Front suspension (MacPherson strut), rear suspension (double wishbone), springs, shock absorbers, control arms, sway bars, alignment specifications Brakes: Front and rear disc brakes, ABS (Anti-lock Braking System), brake hydraulics, caliper specifications, rotor specifications, brake pad replacement Steering: Power steering system, steering rack, tie rods, steering column, wheel alignment Electrical System: Battery, charging system (alternator), starting system (starter motor), lighting (headlights, taillights, interior), fuses, relays, wiring diagrams, body control module (BCM) Body And Interior: Exterior body panels, doors, hood, trunk, interior trim, seats, dashboard, HVAC system, body sealant and rust prevention Diagnostics Troubleshooting: Diagnostic Trouble Codes (DTCs), symptom-based troubleshooting, wiring harness testing, component testing Procedures Included Routine Maintenance: Oil changes, filter replacements, spark plug replacement, coolant flush, brake fluid flush, air filter replacement Engine Repair: Engine rebuild procedures, piston ring replacement, bearing replacement, valve seal replacement, timing belt replacement (critical for EJ series engines) Transmission Repair: Transmission overhaul, clutch replacement, differential service, AWD system maintenance Suspension Steering Repair: Shock absorber and strut replacement, control arm bushings, ball joint replacement, power steering pump service, wheel bearing replacement Brake System Repair: Brake pad and rotor replacement, caliper service, brake line bleeding, ABS module testing Electrical Troubleshooting: Use of wiring diagrams, circuit testing, diagnostic tool usage, component replacement (e.g., alternator, starter, sensors) Bodywork Repair: Panel alignment, dent repair, rust treatment, trim removal and installation Technical Depth Depth Level: Comprehensive factory-level repair and diagnostic information Diagnostic Focus: Detailed diagnostic procedures for all major systems, including Subaru Select Monitor (SSM) interaction where applicable Rebuild Procedures: Full engine and transmission rebuild specifications and procedures Torque Specifications: Detailed torque values for all fasteners and critical components Wiring Diagrams: Complete, high-quality, and easily interpretable wiring diagrams for all vehicle systems 📊 Manual Specifications File Format Digital Format: PDF Print Quality Diagram Quality: High-quality, detailed diagrams and illustrations Text Readability: Clear, concise, and easy-to-read text Binding Type Binding Type Digital: N/A (Digital) Paper Type Paper Type Digital: N/A (Digital) Searchability Text Search: Fully searchable text for quick information retrieval ⚙️ Engine Specifications Primary Engine Wrx Engine: 2.0L EJ205 turbocharged flat-four Sti Engine: 2.5L EJ257 turbocharged flat-four Performance Wrx Horsepower: 227 hp @ 5600 rpm (approx.) Wrx Torque: 217 lb-ft @ 4000 rpm (approx.) Sti Horsepower: 300 hp @ 6000 rpm (approx.) Sti Torque: 300 lb-ft @ 4000 rpm (approx.) Fuel System Fuel Delivery: Sequential Multi-Port Fuel Injection (MPI) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Turbocharger Wrx Turbo Type: TD04L-13T (intercooled) Sti Turbo Type: VF39 (intercooled, larger) on US STI 🔧 Transmission Standard Wrx Transmission: 5-Speed Manual Sti Transmission: 6-Speed Manual Optional Optional Transmission: None for WRX/STI in 2004 Features AWD System: Subaru Symmetrical All-Wheel Drive Sti Center Diff: Driver Controlled Center Differential (DCCD) - electronically controlled Fluid Specs Manual Transmission Fluid: Subaru Extra-S Gear Oil (or equivalent API GL-5 75W-90) 📐 Dimensions Exterior Sedan Wheelbase: 104.9 inches Hatchback Wheelbase: 104.5 inches Sedan Length: 173.8 inches Hatchback Length: 174.4 inches Weights Wrx Curb Weight: 3131 - 3175 lbs (approx.) Sti Curb Weight: 3285 lbs (approx.) Wheel Bolt Pattern: 5x100mm Tires Wrx Tire Size: 215/45R17 Sti Tire Size: 225/45R17 (STI specific tires often used) 🛡️ Safety Features Ratings NHTSA Front Impact: 4-star driver, 5-star passenger (for sedan, general model rating) IIHS Side Impact: Acceptable (for sedan, general model rating) Active Features ABS: Standard (4-wheel ABS) Traction Control: Not...