Porsche 997: Trouble Codes

This article applies to the Porsche 997 (2005-2012).

Your ride’s On-Board Diagnostics II (OBD II) system automatically checks and tests different parts of your car. When your OBD II system detects a problem with one or more components, it triggers a light to go on as a warning. Something as innocuous as a nearly empty washer fluid reservoir can trigger a warning light, but so can something more serious, like a cylinder that is not firing properly. When a light comes on, you should ask your mechanic to run a diagnostic to identify the problem and potential solutions, or if you have a diagnostic tool, you should run the diagnostic to determine the problem and help identify potential solutions. Cylinder misfires and problems with your oxygen sensors are the most common reasons why your check engine light comes on.

Diagnostic Codes

Codes P0300-P0307 – Cylinder Misfire

Your car’s computer has detected that a cylinder is not firing properly. The code usually lists the cylinder where the problem is (e.g., Cylinder #7). Common symptoms include an engine that is harder to start or an engine that stumbles and/or hesitates. Code P0307 can indicate:

• Faulty spark plug or wire
• Faulty coil
• Faulty O2 sensor
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter
• Poor compression
• You’re running out of gas

If the code appears but there are no symptoms, consider resetting the code and seeing if it comes back. If it doesn’t, then you’re likely fine. If it comes back, then:

• Check wiring and connectors that lead into the cylinders, such as your spark plugs.
• Replace engine components (again, like the spark plugs, spark plug wires, and distributor cap) as part of your next round of routine maintenance.
• Check coils, coil packs, and catalytic converter. One Porsche owner reports that if you can smell rotten eggs in your exhaust, then your catalytic converter is likely bad.

Codes P0130-P0160 – Oxygen Sensor-Related Problems

Your car’s computer has detected one or more problems with your oxygen sensors, which are the most important elements of your car’s fuel injection system. The 991 has four O2 sensors: two for each catalytic converter on each side of the car. Common symptoms of a failing O2 sensor include:

• Your car irregularly idles at warm-up or after it’s been running for a while
• Poor or no acceleration
• Backfire
• Poor engine performance
• Poor fuel economy
• Weak driving performance
• Idle, high, or low CO concentration

If the code appears but there are no symptoms, consider resetting the code and seeing if it comes back. If it doesn’t, then you’re likely fine. If it comes back, then it’s likely time to replace the oxygen sensors. Some Porsche owners recommend doing this anyway every 30,000 miles or so.

Porsche 911 (997) Trouble Code Table

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