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Air Injection Pump / Air Injectors
By OE Match
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
This OE Match secondary air injection pump (SIR pump) is an emissions control component designed for Porsche 986 Boxster and Porsche 911 (996) models. It forms part of the secondary air injection system, which pumps fresh air into the exhaust system during cold engine start-up to help reduce emissions.
Fits:
Porsche 986 Boxster / Boxster S 2000 - 2004
Porsche 996 C2 /C4 / C4S 2000 - 2005
Porsche 996 Turbo 2001 - 2005
Diagram ref no 1
This part supersedes earlier Porsche part numbers: 99660510400, 99660510401.
The secondary air injection pump, often referred to as a SIR pump or air injection pump, is a key component in the engine emissions system. It operates primarily during cold starts, forcing fresh air into the exhaust manifold. This additional oxygen helps burn remaining fuel vapours in the exhaust gases before they pass through the catalytic converters.
The OE Match secondary air injection pump follows the original Porsche design specifications for airflow capacity, electrical connections and mounting points. This ensures the pump works correctly with the vehicle’s engine control unit (ECU) and secondary air valves.
When the engine is started cold, the pump injects fresh air into the exhaust system. The extra oxygen promotes more complete combustion of residual hydrocarbons in the exhaust stream and allows the catalytic converters to heat up faster.
This process significantly reduces cold-start emissions and helps the vehicle meet environmental regulations.
Function
• Secondary Air Injection: Pumps fresh air into the exhaust system during cold start
• Emission Reduction: Helps burn unburned hydrocarbons in exhaust gases
• Catalytic Converter Warm-Up: Accelerates catalyst operating temperature
• Engine Management Integration: Works with ECU and secondary air valves
Secondary air pumps operate during every cold start and are exposed to moisture, temperature changes and exhaust gases. Over time the internal motor or pump mechanism may fail, which can trigger a check engine light and increase emissions output. Replacing a faulty pump restores proper operation of the emissions system and ensures efficient engine performance.
When to Replace. Consider replacing the secondary air pump if you notice:
• Check engine light related to secondary air injection faults
• Unusual whining or whistling noise during cold start
• Rough idle during cold start
• Vehicle fails emissions testing
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99660510404
The product you are viewing cross references to these numbers
OEMatch Air Injection Pump / Air Injectors — Fit, Function, Confidence
OEMatch Air Injection Pump / Air Injectors provide replacements and related items for Porsche models. OEMatch focuses on air injection pumps and injectors selected for Porsche applications. These parts support emissions control at cold start and help the catalytic converter reach operating temperature more quickly, improving idle stability until normal running temperature is achieved.
Available Types
- Air injection pumps
- Air injectors
- Associated hoses, check valves and mounting hardware
Understanding OEMatch Air Injection Pump / Air Injectors
OEM (Original Equipment Manufacturer) parts are made by the same company that produced your Porsche’s original air injection pumps and injectors.
OE (Original Equipment) refers to parts matching original specifications for the air injection pumps and injectors and may be supplied by alternative manufacturers. Aftermarket parts offer alternative options, sometimes with enhanced features or better value. OEMatch supplies non-OEM air injection pumps and injectors engineered as direct-fit alternatives to OEM parts, made to original-spec dimensions and tolerances for Porsche models.
The secondary air injection system uses a pump and injectors to introduce fresh air into the exhaust stream during cold starts. This added air accelerates catalytic converter warm-up, encourages combustion of unburnt fuel, reduces hydrocarbon emissions and helps maintain a smooth idle while the engine reaches normal operating temperature.
Benefits Include
- Improved cold-start combustion and smoother idle
- More reliable emissions control during warm-up
- Reduced risk of catalytic converter overheating or contamination
Why Air Injection Pump / Air Injectors Wear and Fail
- Moisture ingress and internal corrosion of pump components
- Carbon and deposit build-up that blocks injector ports or valves
- Cracked or leaking hoses, valves or seals reducing airflow
- Electrical faults, relays or control issues affecting pump operation
The Importance of Replacing with OEMatch Air Injection Pump / Air Injectors
Replacing worn or faulty air injection pumps and injectors restores proper exhaust air delivery during cold start, helping the catalytic converter reach operating temperature promptly and reducing emissions. Timely replacement can improve drivability at idle, prevent downstream exhaust damage and support regulatory compliance for Porsche vehicles where emissions testing applies.
Advantages
- Direct-fit replacements engineered to match original dimensions and tolerances
- Components selected for compatibility with factory mounting points and clearances
- Options for pump, injector and associated hose or valve replacement without replacing unrelated assemblies
