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Porsche > Panamera 971 MK1 (2017-2020) > 971.1 Panamera 4 V6 3.0L 4WD (330 Hp) 2017-20 > Exhausts >

Lambda Sensors / Probes

Lambda Sensors / Probes

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DISPLAYING 1 to 2 (of 2 products)
Lambda Oxygen Sensor, AFTER Catalytic Converter. Porsche 971.1 Panamera 2017-20 - 9A790626550
2
Lambda Oxygen Sensor, AFTER Catalytic Converter. Porsche 971.1 Panamera 2017-20
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9A790626550
Product Information
Product Information
Lambda Oxygen Sensor, AFTER Catalytic Converter.

Restore accurate exhaust-gas monitoring and dependable emissions-system operation with this Porsche Lambda Oxygen Sensor. Designed for compatible Porsche applications, this sensor is positioned AFTER the catalytic converter, where it monitors the oxygen content of exhaust gases after they have passed through the catalyst.

Fits:

  • Porsche 971.1 Panamera V6 3.0L 2WD (330 Hp) 2017-20
  • Porsche 971.1 Panamera 4 V6 3.0L 4WD (330 Hp) 2017-20
  • Porsche 971.1 Panamera 4 V6 3.0L 4WD Executive 2017-20
  • Porsche 971.1 Panamera 4 3.0L Turbocharged V6 Sport Turismo 2017-20
  • Porsche 971.1 Panamera 4S V6 3.0L 4WD (440 Hp) 2017-20
  • Porsche 971.1 Panamera 4S V6 3.0L 4WD Executive 2017-20
  • Porsche 971.1 Panamera 4S 2.9L Twin-Turbo V6 Sport Turismo 2017-19
  • Porsche 971.1 Panamera Turbo V8 4.0L 4WD (550 Hp) 2017-18
  • Porsche 971.1 Panamera Turbo V8 4.0L 4WD Executive 2017-18
  • Porsche 971.1 Panamera Turbo 4.0L Twin-Turbo V8 Sport Turismo 2017-18  

Diagram Ref No 18

Also known as an oxygen sensor, O2 sensor or lambda probe, the downstream sensor provides the engine control unit (ECU) with information that helps assess catalytic converter operation and overall emissions-system performance.

The ECU can compare readings from oxygen sensors positioned before and after the catalytic converter. A correctly functioning catalyst changes the characteristics of the exhaust gases passing through it, and the downstream sensor allows the vehicle to monitor whether this process is occurring as expected.

Lambda sensors operate in an extremely demanding environment, exposed to high exhaust temperatures, vibration, moisture, combustion deposits and repeated thermal cycling. Over time, the sensing element, internal heater, wiring or electrical connections can deteriorate.

Replacing a confirmed faulty sensor with the correct Porsche Lambda Oxygen Sensor 9A790626550 helps restore reliable downstream exhaust monitoring and accurate catalytic converter diagnostics.

What This Product Does:

  • Measures oxygen content in the exhaust gases.
  • Operates AFTER the catalytic converter.
  • Sends exhaust oxygen information to the ECU.
  • Helps monitor catalytic converter performance.
  • Allows comparison with upstream lambda sensor readings.
  • Supports emissions-system diagnostics.
  • Helps detect abnormal catalytic converter behaviour.
  • Provides feedback on downstream exhaust conditions.
  • Supports reliable engine-management monitoring.
  • Helps identify emissions-system faults.
  • Works with the vehicle's wider exhaust and emissions-control system.
  • Replaces a slow, contaminated or failed downstream oxygen sensor.
  • Restores reliable catalyst-monitoring information when sensor failure is confirmed.  

Symptoms Of Wear Or Failure:
  • Check engine or engine-management warning light.
  • Oxygen sensor-related diagnostic fault codes.
  • Downstream lambda sensor fault codes.
  • Catalyst-efficiency-related fault codes.
  • Emissions-system warning messages.
  • Slow oxygen sensor response.
  • Implausible downstream sensor readings.
  • Intermittent sensor signals.
  • Sensor reading remaining unusually fixed.
  • Vehicle failing an emissions test.
  • Increased exhaust emissions.
  • Sensor heater circuit fault.
  • Open- or short-circuit sensor faults.
  • Damaged sensor wiring.
  • Heat-damaged wiring insulation.
  • Corroded or damaged electrical connector.
  • Physical damage to the sensor.
  • Sensor seized into its exhaust mounting point.  

Why Replacement Matters:
  • The downstream oxygen sensor is an important part of the vehicle's emissions-monitoring system.
  • While a before-catalyst sensor is generally more directly involved in air-fuel mixture control, the after-catalyst sensor primarily allows the ECU to monitor the behaviour and efficiency of the catalytic converter.
  • If the downstream sensor becomes slow, inaccurate or completely inoperative, the ECU may no longer receive trustworthy information about exhaust conditions after the catalyst.
  • Replacing a confirmed faulty Porsche Lambda Oxygen Sensor 9A790626550 restores dependable downstream exhaust information and allows the ECU to monitor catalytic converter operation correctly.



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

9A790626550
9A790626550

The product you are viewing cross references to these numbers
Lambda Oxygen Sensor, AFTER Catalytic Converter. Porsche 971.1 Panamera 2017-20 - 9A790626550 - 33798
2
Lambda Oxygen Sensor, AFTER Catalytic Converter. Porsche 971.1 Panamera 2017-20
9A790626550/1
Product Information
Product Information
Lambda Oxygen Sensor, AFTER Catalytic Converter.

Restore accurate exhaust monitoring and dependable emissions-system operation with this OE Match Lambda Oxygen Sensor. Designed for compatible Porsche applications, this sensor is installed AFTER the catalytic converter, where it monitors oxygen levels in the exhaust gases after they have passed through the catalyst.

Fits:

  • Porsche 971.1 Panamera V6 3.0L 2WD (330 Hp) 2017-20
  • Porsche 971.1 Panamera 4 V6 3.0L 4WD (330 Hp) 2017-20
  • Porsche 971.1 Panamera 4 V6 3.0L 4WD Executive 2017-20
  • Porsche 971.1 Panamera 4 3.0L Turbocharged V6 Sport Turismo 2017-20
  • Porsche 971.1 Panamera 4S V6 3.0L 4WD (440 Hp) 2017-20
  • Porsche 971.1 Panamera 4S V6 3.0L 4WD Executive 2017-20
  • Porsche 971.1 Panamera 4S 2.9L Twin-Turbo V6 Sport Turismo 2017-19
  • Porsche 971.1 Panamera Turbo V8 4.0L 4WD (550 Hp) 2017-18
  • Porsche 971.1 Panamera Turbo V8 4.0L 4WD Executive 2017-18
  • Porsche 971.1 Panamera Turbo 4.0L Twin-Turbo V8 Sport Turismo 2017-18  

Diagram Ref No 18

Also known as an oxygen sensor, O2 sensor or lambda probe, the downstream lambda sensor provides important feedback to the engine control unit (ECU). Its primary role is to help the vehicle monitor the performance of the catalytic converter and identify abnormal exhaust or emissions-system behaviour.

The ECU can compare signals from sensors positioned before and after the catalytic converter. This information helps determine whether the catalyst is treating the exhaust gases as expected.

Operating directly in the exhaust system exposes the sensor to high temperatures, vibration, moisture, combustion deposits and repeated thermal cycling. With age, the sensing element can become contaminated or slow to respond, while the internal heater, electrical connector or wiring may also deteriorate.

This OE Match Lambda Oxygen Sensor provides a high-quality replacement for a slow, inaccurate or failed downstream sensor.


What This Product Does:

  • Measures oxygen content in the exhaust gases.
  • Operates AFTER the catalytic converter.
  • Sends exhaust oxygen information to the ECU.
  • Helps monitor catalytic converter performance.
  • Allows comparison with upstream lambda sensor readings.
  • Supports emissions-system diagnostics.
  • Helps detect abnormal catalytic converter behaviour.
  • Provides feedback on downstream exhaust conditions.
  • Supports reliable engine-management monitoring.
  • Helps identify emissions-system faults.
  • Works with the vehicle's wider exhaust and emissions-control system.
  • Replaces a slow, contaminated or failed downstream oxygen sensor.
  • Restores reliable catalyst-monitoring information when sensor failure is confirmed.  

Symptoms Of Wear Or Failure:
  • Check engine or engine-management warning light.
  • Oxygen sensor-related diagnostic fault codes.
  • Downstream lambda sensor fault codes.
  • Catalyst-efficiency-related fault codes.
  • Emissions-system warning messages.
  • Slow oxygen sensor response.
  • Implausible downstream sensor readings.
  • Intermittent sensor signals.
  • Sensor reading remaining unusually fixed.
  • Vehicle failing an emissions test.
  • Increased exhaust emissions.
  • Sensor heater circuit fault.
  • Open- or short-circuit sensor faults.
  • Damaged sensor wiring.
  • Heat-damaged wiring insulation.
  • Corroded or damaged electrical connector.
  • Physical damage to the sensor.
  • Sensor seized into its exhaust mounting point.  

Why Replacement Matters:
  • The downstream oxygen sensor is an important part of the vehicle's emissions-monitoring system.
  • While a before-catalyst sensor is generally more directly involved in air-fuel mixture control, the after-catalyst sensor primarily allows the ECU to monitor the behaviour and efficiency of the catalytic converter.
  • If the downstream sensor becomes slow, inaccurate or completely inoperative, the ECU may no longer receive trustworthy information about exhaust conditions after the catalyst.



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

9A790626550
9A790626550

The product you are viewing cross references to these numbers
DISPLAYING 1 to 2 (of 2 products)
About Lambda Sensors / Probes

Lambda Sensors / Oxygen Probes | Precision Fuel Control & Emissions Performance

Lambda sensors (also known as oxygen sensors or O2 probes) are vital components in your Porsche’s exhaust and fuel management system. These precision sensors monitor the level of oxygen in the exhaust gases and send feedback to the engine control unit (ECU) to maintain the ideal air-fuel ratio. This ensures maximum performance, fuel efficiency, and reduced emissions — essential for both road and track use.

At Design911, we supply a wide range of high-quality replacement lambda sensors specifically designed for Porsche models, including 911, Cayman, Boxster, Panamera, and Macan. Each sensor is built to manufacturer-level standards, ensuring accurate data, fast response times, and long service life even under extreme exhaust temperatures.

Whether you’re performing a maintenance service or troubleshooting an emissions issue, our lambda sensors provide reliable performance and precise air-fuel monitoring to keep your Porsche running at its best.

What Do Lambda Sensors Do?

The lambda sensor continuously measures oxygen content in the exhaust gases, allowing the ECU to adjust the fuel injection and ignition timing. This feedback loop helps the engine maintain an optimal stoichiometric mixture (14.7:1 air to fuel), which is critical for performance, economy, and emissions control.

Core Functions:

  • Monitors exhaust oxygen levels to fine-tune combustion.
  • Supports optimal air-fuel ratio for maximum efficiency.
  • Ensures proper catalytic converter operation.
  • Reduces emissions and maintains environmental compliance.
  • Improves throttle response and fuel economy.

Without a functioning lambda sensor, your engine can run rich or lean — leading to poor performance, excessive fuel use, and potential catalytic converter damage.

Why Do Lambda Sensors Fail?

Lambda sensors operate in one of the harshest environments of the vehicle — exposed to extreme heat, soot, and contaminants. Over time, they wear out and lose accuracy.

Common Causes of Failure Include:

  • Carbon or oil contamination on the sensor element.
  • Thermal shock or excessive heat exposure.
  • Wiring or connector corrosion. Silicone or fuel additive residue buildup.
  • Normal sensor aging and loss of sensitivity.

When a lambda sensor fails, you may notice increased fuel consumption, rough idle, loss of power, or a check engine light — all indicators that replacement is needed.

Why Replace Your Lambda Sensor?

Replacing a worn or faulty lambda sensor restores proper fuel-air mixture control, protects the catalytic converter, and ensures compliance with emission standards.

Key Benefits:

  • Restores fuel efficiency and power delivery. Improves engine responsiveness and idle stability.
  • Reduces harmful emissions and prevents MOT failure.
  • Protects expensive exhaust components like catalytic converters.
  • Direct-fit compatibility for Porsche models.
  • Built from high-grade materials for extended lifespan.

Replacing your lambda sensor is an easy, cost-effective way to revive performance and reliability in your Porsche’s engine system.

Highlights:

  • High-quality oxygen probes and lambda sensors for Porsche.
  • Ensures accurate air-fuel ratio and clean combustion.
  • Compatible with Porsche 911, Cayman, Boxster, Macan, Panamera and others.
  • Corrosion-resistant housings and fast-reacting elements.
  • Essential for performance, emissions control, and fuel economy.
  • Direct-fit design ensures easy installation and reliable connection.

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