🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2004

Chassis Code:

GDB

Engine Code Primary:

EJ207

👋 Introduction

Market Position:

The 2004 Subaru Impreza WRX STI (GDB chassis, Blobeye generation) represented the pinnacle of Subaru's rally-bred performance for its era, targeting enthusiasts seeking high-performance all-wheel-drive capability and a direct connection to motorsports heritage. It competed against other performance sedans and hot hatches, often favored for its unique turbocharged boxer engine and legendary Symmetrical All-Wheel Drive system.

Competitors:

Mitsubishi Lancer Evolution (VIII), Ford Focus RS, Volkswagen Golf GTI (performance variants of the era)

Key Features:

EJ207 2.0L turbocharged boxer engine, Subaru's Symmetrical All-Wheel Drive, DCCD, performance suspension tuning, distinctive 'STI' badging and aerodynamic enhancements.

📋 Manual Details

Areas Covered:

Engine, Drivetrain, Suspension, Steering, Brakes, Electrical Systems, Bodywork, HVAC, Fuel System, Exhaust System, HVAC, SRS Airbags, Security Systems, Emission Control Systems, Diagnostics, Troubleshooting

Page Count:

Approx. 2500-3000 pages (estimated for a comprehensive factory service manual)

Manual Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine Mechanical:

Engine assembly, disassembly, torque specifications, cylinder head, pistons, crankshaft, camshafts, timing belt/chain, lubrication system, cooling system, intake manifold, exhaust manifold, turbocharger systems

Engine Management:

ECU operation, fuel injection system, ignition system, sensor diagnostics, emission control systems, DTC troubleshooting

Drivetrain:

Manual transmission (6-speed), clutch system, viscous center differential, DCCD (Driver's Control Center Differential), front and rear differentials, driveshafts, wheel bearings

Suspension And Steering:

Front struts, rear shock absorbers, control arms, anti-roll bars, power steering system, steering rack, alignment specifications

Brakes:

Front and rear disc brakes, ABS (Anti-lock Braking System), brake caliper service, brake fluid specifications, master cylinder, parking brake

Electrical Systems:

Battery, charging system, starter motor, lighting systems, power windows, power locks, central locking, SRS airbag system, fuse box diagrams, wiring diagrams, body control module (BCM)

Body And Interior:

Body panel removal and installation, interior trim, seats, dashboard, door panels, glass replacement, weatherstripping

HVAC:

Air conditioning system, heater core, blower motor, refrigerant types, troubleshooting

Maintenance:

Scheduled maintenance intervals, oil changes, filter replacements, spark plug replacement, brake fluid flush, coolant flush, differential fluid changes, transmission fluid changes

Repair:

Complete engine rebuild procedures, transmission overhaul, turbocharger replacement, suspension component replacement, brake system repair, electrical component diagnosis and replacement

Troubleshooting:

Diagnostic flowcharts, symptom-based troubleshooting for engine, transmission, electrical, and HVAC issues, wiring diagram interpretation

Diagnostics:

OBD-II diagnostic trouble codes (DTCs), sensor data interpretation, scan tool usage, component testing

Depth:

Comprehensive, covering everything from basic maintenance to complete engine and transmission overhauls. Includes detailed torque specifications, clearances, and repair procedures for professional technicians and advanced DIY enthusiasts.

📊 Manual Specifications

File Format:

PDF

Searchability:

Searchable text

Print Quality:

High-resolution images and diagrams suitable for printing

Binding Type:

N/A (Digital)

Paper Type:

N/A (Digital)

⚙️ Engine Specifications

Engine Type:

Horizontally-opposed turbocharged inline-4 (Boxer)

Displacement:

2.0 Liters (1994 cc)

Engine Code:

EJ207

Horsepower Est:

265 hp @ 6000 rpm (JDM specification)

Torque Est:

253 lb-ft @ 4000 rpm (JDM specification)

Fuel Delivery:

Multi-point Fuel Injection (MPI), Electronic Throttle Control

Fuel Type:

Premium Unleaded Gasoline (91 octane or higher recommended)

ECU Type:

Subaru Engine Control Unit (ECU)

🔧 Transmission

Transmission Type:

6-Speed Manual Transmission

Optional Transmission:

N/A (STI models were exclusively manual)

Dccd:

Driver's Control Center Differential (manual and auto modes)

AWD System:

Symmetrical All-Wheel Drive with viscous center differential

Transmission Fluid Type:

Subaru Extra-S Gear Oil or equivalent API GL-5, SAE 75W-90

Front Differential Fluid Type:

API GL-5, SAE 80W-90

Rear Differential Fluid Type:

API GL-5, SAE 80W-90

📐 Dimensions

Length:

4,485 mm (176.6 in)

Width:

1,740 mm (68.5 in)

Height:

1,415 mm (55.7 in)

Wheelbase:

2,625 mm (103.3 in)

Curb Weight Est:

1,450 kg (3,197 lbs)

Gross Vehicle Weight Rating Est:

1,900 kg (4,189 lbs)

Trunk Volume Est:

0.33 m³ (11.7 cu ft)

🛡️ Safety Features

NHTSA Front Impact Driver:

Good (IIHS - for similar models)

NHTSA Front Impact Passenger:

Good (IIHS - for similar models)

ABS:

Standard Anti-lock Braking System

Traction Control:

Standard

Electronic Brake Force Distribution:

Standard

Airbags:

Driver and front passenger airbags, side curtain airbags (optional/market dependent)

Seatbelts:

3-point front and rear seatbelts with pretensioners and load limiters

💡 Technology Features

Infotainment System:

Basic AM/FM/CD audio system with optional premium sound package. Digital integration was rudimentary compared to modern standards.

Driver Assistance Features:

ABS, Traction Control System (TCS). Limited electronic driver aids beyond these basic systems.

Connectivity Features:

N/A (No Bluetooth, USB, or smartphone integration)

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles (6,000 km) or 6 months, whichever comes first (severe duty driving recommended for performance vehicles)

Engine Oil Filter Replacement:

With every oil change

Air Filter Replacement:

Every 15,000 miles (24,000 km) or 12 months

Spark Plug Replacement:

Every 30,000 miles (48,000 km)

Timing Belt Replacement:

Every 105,000 miles (168,000 km) or 7 years (whichever comes first)

Engine Oil Capacity:

4.5 liters (4.8 US quarts) with filter change

Engine Oil Type:

Synthetic 5W-30 or 0W-30 meeting API SN or ILSAC GF-5 specifications (check owner's manual for exact Subaru recommendations)

Coolant Capacity:

7.0 liters (7.4 US quarts)

Coolant Type:

Subaru Super Coolant (Blue) or equivalent (50/50 mix with distilled water)

Known Issues:

Ringland failure in EJ207 engines (especially if consistently driven hard without proper maintenance or if engine is modified), turbocharger wear, clutch wear, differential issues if not maintained, minor electrical gremlins.

📚 Vehicle History

Brand Heritage:

Subaru has a deep-rooted history in motorsport, particularly in the World Rally Championship (WRC), where the Impreza, driven by legends like Colin McRae and Richard Burns, achieved significant success. This rally pedigree heavily influenced the development of the WRX and STI models, making them synonymous with performance and all-wheel-drive capability.

Model Evolution:

The 2004 model year marked the introduction of the second generation Impreza's mid-cycle refresh, often referred to as the 'Blobeye' due to its distinctive front fascia. This generation (GDB) saw continuous evolution from its rally homologation roots, with the STI variant receiving more potent engines, enhanced suspension, and advanced drivetrain technologies.

Production Period:

2000-2007 (Second Generation GDB)

Assembly Location:

Gunma Plant, Japan

🏆 Awards & Recognition

Awards And Recognitions:

Consistently praised by automotive journalists for its handling, performance, and rally-inspired driving dynamics. Often cited as a benchmark for performance sedans of its era.