Basic checking of Oxygen sensor efficiency using a pinout test harness (Porsche special tool 9543 or equivalent) is described below.
Exhaust system parts can be hot enough to cause serious burns. When working near hot pipes or mufflers, use heavy gloves and other appropriate protection.
For the most accurate test results, the engine must be fully warmed up, the exhaust system must be free of leaks, and all electrical consumers must be off.
^ Disconnect ECM harness connector and connect pinout test harness to ECM under driver's seat.
• Connect a digital voltmeter (millivolt scale) to terminals 24 (Oxygen sensor signal) and 16 or 17 (ground).
— Start engine and let it idle. After a maximum of two minutes oxygen sensor output voltage should begin fluctuating.
Oxygen Sensor Voltage Output
• Engine warm 0.1-0.9 VDC fluctuating
— With engine running, loosen oil filler cap to admit unmeasured intake air and simulate a lean running condition.
• Oxygen sensor output voltage should drop.
Was this article helpful?
The History of Porsche Cars through its generational changes. A must have ebook for any Porsche fanatic, this ebook is a reference book for Porsche enthusiasts. Discover all there is to know about the greatest Porsches ever made. All models are fully described and illustrated providing a definitive production history plus an accurate guide to original specs and equipment.