🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2006 Codes Chassis Code: GDB Engine Code: EJ257 👋 Introduction Market Position Segment: Performance Compact Sedan/Hatchback Target Audience: Enthusiasts, tuners, DIY mechanics, professional technicians Competitive Analysis Competitors: Mitsubishi Lancer Evolution, Subaru WRX (non-STI variants) Key Features Performance Focus: All-wheel drive, turbocharged boxer engine, rally heritage Manual Value Proposition: Empowers owners and technicians with in-depth knowledge for maintenance, repair, and customization 📋 Manual Details Coverage Areas Primary Coverage: Mechanical, Electrical, Body, Diagnostics Secondary Coverage: Maintenance, Repair, Overhaul, Troubleshooting Page Count Estimated Pages: Approximately 3000+ Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: PDF 📖 Manual Coverage Systems Covered Engine Mechanical: Engine assembly, cylinder head, pistons, crankshaft, lubrication, cooling Engine Management: ECU, fuel injection, ignition system, emissions control, turbocharger system Transmission Drivetrain: Manual transmission (TY856), differential, driveshafts, AWD system (DCCD) Suspension Steering: Front and rear suspension, steering gear, power steering Brakes: Brake system, ABS, parking brake, brake fluid specifications Electrical System: Battery, charging system, starting system, lighting, wiring diagrams, fuses, relays Body Exterior: Body panels, doors, hood, trunk, bumpers, exterior trim, glass Body Interior: Interior trim, seats, dashboard, airbags, HVAC system Diagnostics Troubleshooting: On-board diagnostics (OBD-II), DTC codes, symptom-based troubleshooting guides Procedures Included Maintenance: Scheduled maintenance, oil changes, filter replacements, spark plug service Repair Overhaul: Engine rebuild, transmission rebuild, brake caliper replacement, suspension component replacement Diagnostics: Troubleshooting electrical faults, diagnosing engine performance issues Installation Adjustment: Component installation (e.g., clutch, turbocharger), calibration procedures Technical Depth Depth: Comprehensive, covering routine maintenance to major component overhauls and detailed diagnostics Detail Level: Detailed exploded views, torque specifications, diagnostic flowcharts, wiring diagrams 📊 Manual Specifications File Format File Type: PDF Searchability: Searchable text content Printability: Printable pages Print Quality Image Resolution: High-resolution for clear diagrams and illustrations Binding Type Binding: N/A (Digital PDF) Paper Type Paper: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally-opposed turbocharged 4-cylinder (Boxer) Displacement: 2.5 Liters (2457 cc) Engine Code: EJ257 Bore X Stroke: 99.5 mm x 80.0 mm Compression Ratio: 8.2:1 Valve Train: DOHC, 16 valves, belt-driven Performance Horsepower Hp: 300 hp @ 6000 rpm Torque Lb-Ft: 300 lb-ft @ 4000 rpm Redline Rpm: 7000 rpm Fuel System Fuel Delivery: Multi-point Fuel Injection (MPI) Fuel Type: Premium Unleaded Gasoline (91+ Octane Recommended) Turbocharger: IHI VF39 (Domestically Marketed Models) Intercooler: Top-mount air-to-air intercooler 🔧 Transmission Standard Type: 6-Speed Manual Transmission Model Code: TY856 Optional Type: N/A (STI exclusively manual) Features Dccd: Driver Controlled Center Differential (DCCD) with automatic and manual modes AWD System: Symmetrical All-Wheel Drive with viscous coupling center differential and rear limited-slip differential (LSD) Fluid Specifications Transmission Fluid Type: GL-5 Gear Oil (e.g., Subaru Extra-S Gear Oil) Transmission Fluid Capacity: Approx. 2.5 Liters 📐 Dimensions Exterior Length: 4405 mm (173.4 in) Width: 1770 mm (69.7 in) Height: 1440 mm (56.7 in) Wheelbase: 2625 mm (103.3 in) Ground Clearance: 135 mm (5.3 in) Weights Curb Weight: Approx. 1515 kg (3340 lbs) Gross Weight Rating: Approx. 1950 kg (4299 lbs) 🛡️ Safety Features Ratings NHTSA Front Crash Rating: 4 Stars (Driver), 5 Stars (Passenger) IIHS Crash Test Ratings: Good (Frontal Offset), Acceptable (Side Impact) Active Features ABS: Standard Anti-lock Braking System Ebs: Electronic Brake-force Distribution (EBD) Traction Control: Traction Control System (TCS) Passive Features Airbags: Driver and front passenger airbags, front side airbags Seatbelts: 3-point front and rear seatbelts with pre-tensioners Rollover Protection: Reinforced body structure 💡 Technology Features Infotainment Head Unit: Factory AM/FM/CD audio system with optional subwoofer Display: Basic LCD display for audio and climate Driver Assistance Cruise Control: Standard Cruise Control All Wheel Drive: Advanced Symmetrical AWD with DCCD for dynamic torque distribution Connectivity Aux Input: Optional auxiliary audio input 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 3 months (severe duty/enthusiast driving) or 7,500 miles or 6 months (normal duty) Air Filter Replacement: Every 15,000 miles or 12 months Spark Plug Replacement: Every 60,000 miles (iridium type) Timing Belt Replacement: Every 105,000 miles or 7 years (refer to manual for exact interval) Fluid Specifications Engine Oil Type: 0W-30 Synthetic (API SN or higher recommended, SAE 5W-30 acceptable) Engine Oil Capacity: Approx. 4.8 US quarts (4.6 L) with filter change Coolant Type: Subaru Super Coolant (Blue) or equivalent (50/50 mix with distilled water) Brake Fluid Type: DOT 3 or DOT 4 Known Issues Head Gaskets: While less common on EJ257 than earlier EJ25s, coolant leaks can still occur. Manual details inspection and replacement. Ringland Failure: Potential for piston ringland failure under high boost/improper tuning. Manual provides diagnostic steps. Clutch Wear: Can be subject to accelerated wear due to performance driving. Manual covers clutch inspection and replacement. Turbocharger Wear: VF39 turbo can develop shaft play over time. Manual offers troubleshooting and rebuild guidance. 📚 Vehicle History Brand Heritage Motorsport Roots: Subaru's extensive rally history, particularly in the World Rally Championship...