Porsche Leakage Diagnosis Pump Part Number: How to Identify and Replace It

If you own a Porsche with a leak diagnosis pump (also called a leak detection pump, LDP, or DMTL pump), you've likely encountered a check engine light and a diagnostic code pointing to this component. Finding the correct part number is essential for a proper fix. This guide explains what the leakage diagnosis pump does, why the part number matters, how to find it for your specific Porsche model, and common part numbers across different generations.

What Is a Leakage Diagnosis Pump in a Porsche?

The leakage diagnosis pump is part of the evaporative emission control (EVAP) system. Its job is to pressurize the fuel system and detect any vapor leaks. When the pump detects a leak that exceeds the allowed threshold, it triggers a check engine light and stores a trouble code. Common codes include P0442, P0455, or P0456. The pump itself is usually mounted near the fuel tank or in the rear wheel well. Over time, the diaphragm can fail, the motor can seize, or the internal seals can leak.

Why the Correct Part Number Matters

Porsche uses several variations of the leakage diagnosis pump depending on the model, model year, engine size, and even market (US vs. RoW). Using the wrong part can lead to improper fit, electrical connector mismatch, or incorrect EVAP system function. Additionally, some aftermarket pumps claim compatibility but may not meet OEM specifications, potentially causing false leak codes. Therefore, always verify the original part number before purchasing.

How to Find the Leakage Diagnosis Pump Part Number for Your Porsche

There are a few reliable ways to locate the part number:

1. Check the pump itself. Look on the side or top of the pump housing for a white sticker or engraved number. It typically starts with a 7-digit number like 958-XXX-XXX or 996-XXX-XXX.
2. Use your vehicle identification number (VIN). Contact a Porsche dealer or enter your VIN on a genuine parts website to cross-reference the correct part. For DIYers, many online OEM parts catalogs allow VIN-based search.
3. Refer to your service manual or ETKA (electronic parts catalog). These provide exploded diagrams and part numbers broken down by model and year.
4. Google the old part number or the fault code along with your model (e.g., "P0442 Cayenne 2011 part number" to see forum discussions.

Common Porsche Leakage Diagnosis Pump Part Numbers by Model

Below are frequently encountered part numbers for popular Porsche models. Always confirm against your VIN as production changes may have occurred.

Porsche Cayenne (955 / 957 / 958)

• 955-125-144-00 / 955-125-144-01 – Early Cayenne (2003-2010) – may be superseded by later number.
• 958-125-244-00 – Cayenne 958 (2011-2014) – common on V6 and V8 engines.
• 958-125-244-10 – Updated version for MY2015+ (9Y0 generation) and some late 958 models.

Porsche Panamera (970 / 971)

• 970-125-244-00 – Panamera 970 (2010-2016) – used with both naturally aspirated and turbo engines.
• 971-125-244-00 – Panamera 971 (2017+) – note: check for vibration dampener differences.

Porsche Macan (95B)

• 95B-125-244-00 – Macan (2015-2022) – some models may require a bracket adapter; verify with VIN.

Porsche 911 (996 / 997 / 991)

• 996-125-144-01 – 996 generation (1998-2004), including Carrera, Turbo, GT3.
• 997-125-144-00 – 997 generation (2005-2012) – a few iterations exist; check supersession.
• 991-125-244-00 – 991 generation (2012-2018) – common for most Carrera and Turbo models.

Porsche Boxster / Cayman (986 / 987 / 981 / 718)

• 986-125-144-00 – 986 Boxster (1997-2004).
• 987-125-144-01 – 987 Boxster/Cayman (2005-2012).
• 981-125-244-00 – 981 generation (2013-2016).
• 9A1-125-244-00 – 718 Boxster/Cayman (2017+), but confirm with VIN.

Aftermarket vs. OEM Replacement

You have three main options for replacement:

1. OEM (Original Equipment Manufacturer) – Bought from Porsche or a certified dealer. Most expensive but guaranteed fit and function. Often comes with a new bracket or gasket.
2. OEM supplier (e.g., Hella, Pierburg, Bosch) – Many Porsche pumps are manufactured by these companies; you can buy the same part without the Porsche logo at a lower price. Cross-reference the OE number with the supplier's catalog.
3. Aftermarket – Brands like URO, Febi, or Vaico offer budget-friendly pumps. Quality varies; some may have shorter lifespan or cause intermittent codes. Read reviews and compare warranty periods.

For most owners, OEM or OEM-supplier (Hella/Pierburg) is recommended for reliability. If your car is older and you plan to keep it short-term, an aftermarket unit may suffice.

Step-by-Step Replacement Guide

Replacing the leakage diagnosis pump is typically a straightforward DIY task on most Porsches, but difficulty varies.

1. Safety first. Disconnect the battery negative terminal. Work on a cooled engine. Have a fire extinguisher nearby (gasoline vapors).
2. Locate the pump. On Cayenne/Macan, it's behind the left rear wheel well cover (access from inside the wheel well or under the car). On 911/Boxster/Cayman, it's near the fuel tank on the passenger side, often under a plastic cover. On Panamera, check the rear driver side near the tank.
3. Remove the electrical connector. Press the locking tab and pull straight out. Inspect pins for corrosion.
4. Disconnect the vapor hoses. Use a hose clamp tool or pliers. Note the routing: usually two hoses: one to the tank, one to the atmosphere. Take a photo before removal.
5. Remove the mounting bolts. Usually two or three 10mm or 8mm bolts. Keep them safe.
6. Install the new pump. Match the orientation. Reconnect hoses (push firmly until you hear a click). Plug in the electrical connector.
7. Clear the fault codes and perform a leak test using a diagnostic tool (e.g., Durametric, VCDS, or a generic scanner). Some pumps self-test after a few drive cycles.

If you encounter a code that returns immediately, double-check hose connections and that the pump is the correct part number for your vehicle.

Final Recommendation

When your Porsche's check engine light comes on with an EVAP leak code, verifying the leakage diagnosis pump part number is the first step. Start by checking the part number on your existing pump. If it's unreadable, use your VIN to look up the correct OEM number from a reliable source. For most models, the Hella or Pierburg pumps with the same part number provide excellent quality at a lower cost than the dealership. Do not rely on generic listings that claim universal fit. Always confirm with your specific VIN. If you're not comfortable replacing it yourself, a Porsche specialist can do it in under an hour. Proper diagnosis and correct part selection will save you time and prevent repeat repairs.