The PCV (Positive Crankcase Ventilation) system is designed to regulate and remove fumes from the engine crankcase, and to alleviate crankcase pressure which could cause oil leaks or seal damage. The PCV system routes crankcase fumes into the intake manifold where they can be burned to eliminate harmful emissions into the atmosphere. The PCV valve controls the amount of crankcase flow volume depending on the engine's load. With large throttle openings (high engine loads), more blow-by gases are produced and the PCV system flows more oil vapor into the intake manifold. The PCV valve also functions as a check valve to prevent the intake manifold flow from reversing back into the crankcase when there is a backfire, or during periods of high manifold pressure (boost) during forced induction by a turbocharger or supercharger.
However, oil residue can accumulate inside the intake manifold, throttle body, intake track and even the air filter during aggressive driving conditions. There are various negative effects when excess oil vapor contaminates the intake system from the stock PCV system, such as:

First, remove the oil filler...

First, remove the oil filler cap to facilitate removing the fuel rail cover.

Next, remove the RH side (passenger's...

Next, remove the RH side (passenger's side) plastic fuel rail cover by carefully pulling it upward (the cover is held in place by snaps). After the cover is removed, it is advisable to reinstall the oil filler cap to prevent any debris from entering the engine.

Disconnect the PCV hose that...

Disconnect the PCV hose that goes into the manifold vacuum connector by pulling it off (spark plug boot pliers or needle-nose pliers may make grasping it for removal a bit easier).
• Throttle body and/or MAFS (Mass Air Flow Sensor) malfunction or failure.
• Air filter, intercooler (if equipped) and intake ducting contamination if oil pools and runs back out the intake system after engine shutdown.
• Reduced octane of the air/fuel mixture, which can cause detonation and the ECM (Engine Control Module) to retard timing, thereby reducing engine power.
• Excessive carbon build-up on valves, piston crowns, combustion chambers and spark plugs. This also increases the chance of detonation and power loss.
• Increased emissions & possible contamination of catalytic converters and oxygen sensors.
So, the bottom line is that excessive oil vapor in the intake manifold is detrimental to your engine. The fix is to install an Elite Engineering PCV catch can, and here's how!

The Elite Engineering catch...

The Elite Engineering catch can mounting bracket attaches to the engine block with two supplied 10mm button-cap bolts (on the C5); on the C6 an extension tube (supplied) is required to move the bracket out from the engine block and is secured using the supplied bolt and washer. This extension tube is visible just to the left of the black catch can mounting bracket on this C6.

Here's the catch can attached...

Here's the catch can attached to the block as seen from above on the passenger side.

Here's the view looking across...

Here's the view looking across at the catch can from the driver's side prior to attaching the hoses.
| Difficulty Index - 2 Wrenches |
| Anyone’s Project: no tools required | 1 Wrench |
| Beginner: basic tools | 2 Wrenches |
| Experienced: special tools | 3 Wrenches |
| Accomplished: special tools and outside help | 4 Wrenches |
| Professionals Only: send this work out | 5 Wrenches |
| Parts List |
| Tools Required |
| Flat-blade screwdriver, slip-joint pliers, utility knife or shears, metric Allen wrenches |
| Time Required |
1 HOUR |

Attach the supplied 3/8-inch...

Attach the supplied 3/8-inch inside-diameter hose to the manifold vacuum connector and secure it with one of the supplied hose clamps. Use a utility knife or shears to cut the hose to a length where it will attach to the lower catch can fitting without kinking, then attach it to this fitting and secure with a hose clamp.

Connect the remaining length...

Connect the remaining length of hose to the PCV hose line you originally disconnected from the manifold, using a hose clamp to secure it. Trim the hose so that it connects to the upper fitting of the catch can, push it on and secure it with the last hose clamp.

Replace the fuel rail cover...

Replace the fuel rail cover and oil filler cap and you're done. Here's what the completed installation looks like on a C6. The Elite Engineering catch cans are available in black, red, blue or silver anodized aluminum.