Oxygen Sensor
- With engine at operating temperature of 176°F (80°C), check for leaks in exhaust system. Using Adapter (Sun 120 239), connect CO test equipment hose to the sampling point on left exhaust pipe.
- Let engine run about 2 minutes at idle and read CO content. Check function of oxygen regulation. Pull hose off of pressure regulator and pinch off. CO content must rise briefly and then drop again.
- If test is not okay, disconnect connector at pressure regulator and hold control wire to ground. CO should rise. Connect control unit wire connector to connector of alternator. CO should drop.
- If test is not okay, check wire connection on control unit. If test is okay, replace control unit. If test step 2) is not okay, but test step 3) is okay, replace defective oxygen sensor.