APR PCV System Upgrade with Catch Can - VW/Audi / EA888.4 / GTI / Golf R / Tiguan / Arteon / A3 / S3 / A4 / A5 / Q3

The factory EA888 Gen 4 PCV system regulates crankcase pressure with a spring-loaded diaphragm, its most common failure point. Under heavy load it struggles to hold vacuum, and an internal bypass valve opens that sends crankcase vapors around the factory cyclone oil separator. Tuned, highly boosted engines push more blow-by through the system than the factory parts were sized for. The APR PCV System Upgrade with Catch Can replaces the diaphragm with calibrated static orifices that do not wear out. Internal one-way valves send crankcase and EVAP gases into the intake manifold when the engine is off boost and into the turbo inlet when it is in boost, and a less restrictive path to the turbocharger's suction jet pump pulls nearly twice the factory vacuum at full boost. Every factory flow path is retained, and crankcase pressure stays negative whether the engine is coasting or in boost. Oil separation improves too. Crankcase vapors pass through the engine's internal baffles, then an impact surface inside the APR top plate that catches fine oil particles and drains them back to the sump, then the catch can. In-house fluoroelastomer seals rated to 430°F and PTFE-lined -10 AN hoses handle every fuel, including ethanol, with no vapor odor in the engine bay. APR logged crankcase pressure over more than 1,000 miles on five cars, from daily commutes and highway trips to track days and autocross. The system needs no ECU changes, triggers no check engine light, satisfies every emissions parameter the ECU monitors, and installs at home in about an hour.