Positioning:
        
        
            The Subaru Impreza of this era (2nd generation, GD/GG chassis) was positioned as a compact, sporty, and capable all-wheel-drive vehicle, with the WRX variant being a performance icon in the rally-inspired sedan market.
        
     
    
    
        
            Competitors:
        
        
            Competed with vehicles like Mitsubishi Lancer, Honda Civic Si, Volkswagen Golf GTI, and Ford Focus.
        
     
    
    
        
            All Wheel Drive:
        
        
            Standard Symmetrical All-Wheel Drive (SAWD) system, a hallmark of Subaru, providing excellent traction and stability in various conditions.
        
     
    
        
            Performance Variants:
        
        
            Availability of high-performance WRX models with turbocharged engines and sport-tuned suspensions.
        
     
    
        
            Practicality:
        
        
            Offered in both sedan and wagon (outback sport/sport wagon) body styles, providing versatility for different needs.
        
     
    
    
        
            Purpose:
        
        
            To provide comprehensive technical information for diagnosing, repairing, and maintaining the 2001 Subaru Impreza, empowering both professional technicians and dedicated enthusiasts.
        
     
 
    
    
    
        
            Engine:
        
        
            Detailed diagnostics, repair procedures, component specifications for EJ251 (2.5L SOHC) and EJ205 (2.0L Turbocharged DOHC - WRX models) engines.
        
     
    
        
            Transmission:
        
        
            Manual (5-speed), Automatic (4-speed) transmission disassembly, assembly, adjustments, diagnostics, and fluid specifications.
        
     
    
        
            Drivetrain:
        
        
            All-Wheel Drive (AWD) system: differentials (front, center, rear), driveshafts, CV joints, hub bearings, maintenance, and repair.
        
     
    
        
            Suspension:
        
        
            Front and rear suspension: struts, springs, control arms, sway bars, bushings, alignment specifications, component replacement.
        
     
    
        
            Brakes:
        
        
            Front and rear brake systems: disc brakes, calipers, pads, rotors, master cylinder, brake lines, ABS system diagnostics and components.
        
     
    
        
            Steering:
        
        
            Power steering system: pump, reservoir, lines, rack and pinion, steering column, tie rods, wheel alignment.
        
     
    
        
            Electrical:
        
        
            Complete electrical schematics, wiring diagrams, fuse and relay locations, battery, charging system, starter, lighting, power windows, locks, wipers, HVAC controls, ECU diagnostics.
        
     
    
        
            Body:
        
        
            Exterior and interior body panels, doors, hood, trunk, bumpers, glass, trim, seat removal, sound deadening.
        
     
    
        
            HVAC:
        
        
            Heating, Ventilation, and Air Conditioning: A/C compressor, refrigerant, condenser, evaporator, blower motor, controls, troubleshooting.
        
     
    
        
            Fuel System:
        
        
            Fuel pump, fuel injectors, fuel filter, fuel pressure regulator, evaporative emissions (EVAP) system.
        
     
    
        
            Cooling System:
        
        
            Radiator, thermostat, water pump, coolant hoses, fan clutch/electric fan, expansion tank, flush and refill procedures.
        
     
    
        
            Exhaust System:
        
        
            Exhaust manifold, catalytic converter, muffler, exhaust pipes, oxygen sensors.
        
     
    
    
        
            Maintenance:
        
        
            Oil changes, filter replacements (oil, air, fuel, cabin), spark plug replacement, fluid flushes (coolant, brake, transmission, differential), tire rotation, brake pad inspection/replacement, battery testing.
        
     
    
        
            Repair:
        
        
            Engine overhaul, cylinder head gasket replacement, clutch replacement, turbocharger replacement (WRX), transmission rebuild, brake caliper/rotor replacement, suspension component replacement, starter/alternator replacement.
        
     
    
        
            Diagnostics:
        
        
            Troubleshooting guides for common symptoms, DTC (Diagnostic Trouble Code) lookup and interpretation, starting system, charging system, fuel system, ignition system diagnostics, ABS system diagnostics.
        
     
    
        
            Adjustments:
        
        
            Parking brake adjustment, clutch pedal adjustment, idle speed adjustment (older models), wheel alignment procedures.
        
     
    
        
            Troubleshooting:
        
        
            Systematic approaches to diagnose issues like poor starting, rough idle, overheating, braking problems, electrical malfunctions.
        
     
    
    
        
            Depth:
        
        
            Comprehensive, covering from basic preventative maintenance to complete engine and transmission rebuilds, including detailed electrical schematics and diagnostic procedures.
        
     
    
        
            Target Audience:
        
        
            Professional Automotive Technicians, Advanced DIY Mechanics, Enthusiasts seeking in-depth repair knowledge.
        
     
 
    
    
    
    
        
            Engine Displacement Na:
        
        
            2.5 Liters (2457 cc)
        
     
    
        
            Engine Type Na:
        
        
            Naturally Aspirated, Horizontally Opposed (Boxer), SOHC, 16-valve, 4-cylinder
        
     
    
        
            Bore X Stroke Na:
        
        
            99.5 mm x 79.0 mm
        
     
    
        
            Compression Ratio Na:
        
        
            9.7:1
        
     
    
        
            Horsepower Na:
        
        
            165 hp @ 5,600 rpm
        
     
    
        
            Torque Na:
        
        
            166 lb-ft @ 4,000 rpm
        
     
    
    
        
            Engine Code Turbo:
        
        
            EJ205 (for WRX models)
        
     
    
        
            Engine Displacement Turbo:
        
        
            2.0 Liters (1994 cc)
        
     
    
        
            Engine Type Turbo:
        
        
            Turbocharged, Horizontally Opposed (Boxer), DOHC, 16-valve, 4-cylinder
        
     
    
        
            Horsepower Turbo:
        
        
            227 hp @ 5,600 rpm (WRX)
        
     
    
        
            Torque Turbo:
        
        
            217 lb-ft @ 4,000 rpm (WRX)
        
     
    
    
        
            Fuel Delivery:
        
        
            Multi-point Fuel Injection (MPI)
        
     
    
        
            Fuel Type:
        
        
            Unleaded gasoline (87 octane minimum for NA, 91 octane recommended for WRX)
        
     
    
    
        
            Ignition Type:
        
        
            Distributorless Ignition System (DIS) with Coil-on-Plug (COP) or Coil-Near-Plug (CNP) depending on specific sub-model/engine.
        
     
 
    
    
    
        
            Length Sedan:
        
        
            Approx. 4410 mm (173.6 inches)
        
     
    
        
            Width Sedan:
        
        
            Approx. 1700 mm (66.9 inches)
        
     
    
        
            Height Sedan:
        
        
            Approx. 1410 mm (55.5 inches)
        
     
    
        
            Wheelbase:
        
        
            Approx. 2515 mm (99.0 inches)
        
     
    
        
            Track Width Front:
        
        
            Approx. 1465 mm (57.7 inches)
        
     
    
        
            Track Width Rear:
        
        
            Approx. 1460 mm (57.5 inches)
        
     
    
        
            Length Wagon:
        
        
            Approx. 4465 mm (175.8 inches)
        
     
    
        
            Height Wagon:
        
        
            Approx. 1465 mm (57.7 inches)
        
     
    
    
        
            Curb Weight Sedan Na:
        
        
            Approx. 1300-1350 kg (2866-2976 lbs)
        
     
    
        
            Curb Weight Sedan Wrx:
        
        
            Approx. 1300-1350 kg (2866-2976 lbs)
        
     
    
        
            Gross Vehicle Weight Rating:
        
        
            Varies by model and trim
        
     
    
        
            Towing Capacity:
        
        
            Not typically specified or recommended for this model
        
     
    
        
            Wheelbase Wagon:
        
        
            Approx. 2515 mm (99.0 inches)
        
     
    
    
        
            Cargo Volume Sedan:
        
        
            Approx. 12.6 cu ft
        
     
    
        
            Cargo Volume Wagon:
        
        
            Approx. 37.1 cu ft (with rear seats up)
        
     
    
    
        
            Wheel Bolt Pattern:
        
        
            5 x 100 mm
        
     
    
        
            Standard Tire Size Na:
        
        
            205/55R16
        
     
    
        
            Standard Tire Size Wrx:
        
        
            205/55R16 (WRX), 205/50R17 optional on later 2001 models or WRX STi
        
     
    
        
            Standard Wheel Size:
        
        
            16 x 6.5 inches
        
     
 
    
    
    
        
            Oil Change Interval:
        
        
            Every 3,000-7,500 miles (10,000 km) or 6-12 months, depending on driving conditions and oil type (refer to manual for specifics).
        
     
    
        
            Air Filter Replacement:
        
        
            Every 15,000-30,000 miles (24,000-48,000 km) or as needed based on inspection.
        
     
    
        
            Cabin Air Filter Replacement:
        
        
            Every 15,000-20,000 miles (24,000-32,000 km)
        
     
    
        
            Spark Plug Replacement Na:
        
        
            Approx. 60,000-100,000 miles (96,000-160,000 km) for iridium-tipped plugs.
        
     
    
        
            Coolant Replacement:
        
        
            Every 30,000 miles (48,000 km) or 2 years for conventional coolant, longer for Subaru Super Coolant.
        
     
    
        
            Timing Belt Replacement:
        
        
            Crucial: Every 90,000-105,000 miles (144,000-168,000 km) or 7-10 years due to SOHC engine interference design. (WRX models also require timing belt replacement).
        
     
    
    
        
            Engine Oil Type:
        
        
            SAE 5W-30 (API SG, SH, SJ, SL, or ILSAC GF-2 or GF-3)
        
     
    
        
            Engine Oil Capacity Na:
        
        
            Approx. 4.5 US quarts (4.3 L) with filter
        
     
    
        
            Engine Oil Capacity Wrx:
        
        
            Approx. 4.5 US quarts (4.3 L) with filter (EJ205)
        
     
    
        
            Coolant Type:
        
        
            Subaru Anti-freeze/Coolant (Blue) or equivalent ethylene glycol-based coolant with Subaru's specific additive package
        
     
    
        
            Brake Fluid Type:
        
        
            DOT 3 or DOT 4
        
     
    
        
            Power Steering Fluid:
        
        
            Subaru Genuine Power Steering Fluid (or equivalent Dexron III compatible)
        
     
    
    
        
            Head Gaskets:
        
        
            While less prevalent than on earlier EJ22/EJ25 engines, the EJ251 SOHC engine can still experience head gasket failures, particularly under high heat or stress. The manual will detail diagnostic and replacement procedures.
        
     
    
        
            Wheel Bearings:
        
        
            Front wheel bearings can be prone to wear, leading to humming or grinding noises. Manual covers replacement procedures.
        
     
    
        
            Cv Axles:
        
        
            Front CV axle boots can tear, leading to grease loss and potential joint failure. Manual provides replacement steps.
        
     
    
        
            Clutch Wear:
        
        
            Clutch wear is normal, but early failure can sometimes be linked to improper use or hydraulic system issues. Manual covers replacement and bleeding.
        
     
    
        
            Turbo Failure Wrx:
        
        
            EJ205 turbochargers can experience wear or failure if not properly maintained or if oil supply is compromised. Manual covers diagnostics and replacement.
        
     
    
        
            Oil Leaks:
        
        
            Valve cover gaskets and oil pan gaskets can degrade and leak over time. Manual details replacement.
        
     
 
    
    
    
        
            Subaru Legacy Connection:
        
        
            The Impreza platform shared many components and design philosophies with its larger sibling, the Subaru Legacy.
        
     
    
    
        
            First Generation:
        
        
            First introduced globally in 1992, replacing the Subaru Leone.
        
     
    
        
            Second Generation Launch:
        
        
            The second generation (GD/GG chassis) was launched in 2000 for the 2001 model year, featuring a significant redesign.
        
     
    
        
            Design Influence:
        
        
            This generation saw the introduction of the controversial 'bug eye' headlights for the early models, later updated in subsequent facelifts.
        
     
    
        
            Wrx Significance:
        
        
            The WRX model gained significant popularity due to its rally racing heritage and accessible performance.
        
     
    
    
        
            Production Locations:
        
        
            Primarily manufactured in Japan by Subaru Corporation (formerly Fuji Heavy Industries).