034Motorsport Silicone PRV Pipe to Turbo Inlet Hose for Audi A4 and A4 Quattro 1.8T (2004–2006)

Built from 4-ply high-temperature automotive grade silicone, the 034Motorsport 034-104-2003 is the hose that joins the PRV pipe to the turbo inlet on B6-generation Audi A4 and A4 Quattro models with the 1.8T engine. The factory rubber hose here is a very common point of failure. It almost always rips when the turbo inlet hose or the PRV pipe is removed, and it tends to crumble with age. The silicone replacement will not crumble apart or rip the way the factory rubber hose does. It cross-references to factory numbers 06B 103 493 AE and 06B 103 493 AB.

This 034Motorsport hose carries a 24-month warranty.

The hose belongs to the crankcase ventilation system. That system routes pressurized crankcase air through an air/oil separator, sending oil vapor back to the engine and clean air to the intake side. Because this hose meets the turbo inlet, a tear lets unmetered air into the intake tract. Two factory numbers apply to this position, and the 034Motorsport hose covers both. It is made in the United States. 034Motorsport designs, tests, and builds its parts in-house at its Fremont, California facility.

Technical Details

• Manufacturer: 034Motorsport
• Part number: 034-104-2003
• Position: PRV pipe to turbo inlet
• Engine: B6 1.8T
• Material: 4-ply high-temperature automotive grade silicone
• Cross-references factory numbers 06B 103 493 AE and 06B 103 493 AB
• Made in the United States
• Warranty: 24 months

Common Questions

Why does the factory hose fail so often?
The factory hose is rubber. It almost always rips when the turbo inlet hose or PRV pipe comes off, and it crumbles over time.

What symptoms can a torn hose cause?
Unmetered air can set a check engine light for an intake leak or another airflow code. A severe leak can cause rough running or a misfire, and oil residue often shows up around the hose.

Does it fit the A4 Cabriolet?
The fitment table below shows the body styles and years covered, including Cabriolet applications.

Fitment & Compatibility

Check the fitment table below for the vehicles this hose fits. Confirm that your car has the 1.8T engine and matches the body style shown. Send us your VIN and we will verify the fit.