How to Install Precision Works Catch Can on Mercedes M156

Quick Answer

Install the Precision Works Engine Oil Catch Can Kit on your Mercedes M156 AMG by routing the supplied hoses from the crankcase ventilation to the catch can, using the billet CNC-machined fittings included in the kit. This reduces oil buildup in the intake and helps keep the engine bay clean.

Installation Steps

1. 1. Prepare the Engine Bay: Disconnect the negative battery terminal and allow the engine to cool completely. Remove any engine covers that block access to the crankcase ventilation hoses on the intake side. Working on a hot engine can cause burns or damage to plastic fittings. Always let it cool for at least 30 minutes.
2. 2. Locate the Crankcase Ventilation Hose: Find the factory PCV hose running from the valve cover to the intake tube. On M156 engines, this is typically a rubber hose near the throttle body. Mark its routing with tape or a photo for reference. If you mix up the hose routing, the catch can may not function correctly. Take a photo before disconnecting.
3. 3. Disconnect and Remove the Factory Hose: Carefully loosen the clamps and pull the factory hose off its fittings. Use a pick tool if the hose is stuck. Set the hose aside—you may need it for a future reinstall. Avoid using excessive force that could crack the plastic intake tube. Apply penetrating oil if the hose is seized.
4. 4. Mount the Catch Can: Choose a secure mounting location on the inner fender or chassis rail near the intake. Use the supplied brackets or a self-tapping screw. Ensure the can is upright and will not interfere with hood closure or moving parts. A loose catch can can vibrate and cause hose connections to fail. Double-check the mount is solid.
5. 5. Connect the Hoses: Cut the supplied 10 ft. hose to length. Attach one end to the valve cover outlet and the other to the catch can inlet (marked IN). Run a second hose from the catch can outlet (OUT) back to the intake tube. Use the supplied clamps at each connection. Reversing the inlet and outlet will starve the engine of ventilation. Verify the arrows on the catch can match airflow direction.
6. 6. Secure and Test: Tighten all clamps, ensure hoses are not kinked, and reconnect the battery. Start the engine and check for leaks at idle and under light revs. Drive briefly and inspect the can for proper oil collection. A small amount of oil in the can after a short drive is normal. If you see none, recheck the hose connections for vacuum leaks.

Product Details

• Precision Works Engine Oil Catch Can Kit - Mercedes M156 AMG Engines: Includes Precision Works billet CNC machined fittings, 10 ft. of hose, clamps, and oil catch can. You get a complete kit with no need to source extra parts—just mount the can and connect the hoses.