This comprehensive 2004 Subaru Impreza WRX & STI Factory Service Repair Manual provides everything you need to perform routine maintenance and complex repairs on your vehicle. Whether you're a seasoned professional mechanic or a dedicated DIY enthusiast, this manual offers detailed instructions and clear diagrams to help you work confidently. The manual covers a wide range of topics, including routine maintenance procedures, tune-up specifications, engine removal and installation, cylinder head and valve train repair, engine block diagnostics, lubrication system maintenance, intake and exhaust system repair, cooling and heating system service, fuel and emissions system troubleshooting, transaxle repair, clutch replacement, manual and automatic transmission repair, differential maintenance, driveshaft replacement, steering system adjustments, suspension repairs, brake system service (including ABS), bodywork repair, heater and air conditioning system servicing, automatic climate control system diagnostics, electrical system troubleshooting (including SRS), supplemental restraint system (SRS) repair, engine repair, air conditioning system service, exhaust system repair, emissions control system maintenance, ignition system diagnostics, steering system repair, wiring diagrams, valve timing procedures, chain and gear replacement instructions, general removal and installation guidelines, safety precautions, special tool requirements, tensioner adjustments, tightening torques, timing mark identification, valve timing instructions, tensioner release and reset methods, chain routing, and sprocket/gear valve timing mark identification. This manual is your indispensable resource for ensuring your Subaru Impreza WRX or STI runs smoothly and reliably for years to come.

The 2004 Subaru Impreza WRX and STI were high-performance versions of the popular Impreza compact car, known for their rally-bred heritage and impressive performance capabilities. Both models shared the same basic platform, but the STI boasted a more powerful engine and enhanced performance features, making it the top-of-the-line option. Under the hood, the WRX housed a turbocharged 2.0-liter boxer engine, producing around 227 horsepower and 221 lb-ft of torque, while the STI received a larger turbocharger and other enhancements, resulting in a potent 300 horsepower and 305 lb-ft of torque. Both models featured Subaru's signature Symmetrical All-Wheel Drive (AWD) system, which provided exceptional traction and handling in all weather conditions. The WRX came standard with a 5-speed manual transmission, while the STI offered a 6-speed manual as standard, with a 4-speed automatic transmission available as an option. Beyond the powertrain, the WRX and STI featured distinct styling cues that differentiated them from the standard Impreza. The WRX featured a more aggressive front bumper with larger air intakes, side skirts, a rear spoiler, and unique alloy wheels. The STI took it a step further with a more prominent rear spoiler, larger exhaust tips, and special STI badging. Inside, both models featured sporty interiors with supportive bucket seats, a leather-wrapped steering wheel, and a center console focused on driver ergonomics. The 2004 Impreza WRX and STI were significant vehicles in Subaru's history, further solidifying their reputation for performance and all-wheel drive prowess. Despite their age, they remain popular choices for enthusiasts seeking a reliable and engaging driving experience.