Mystery "Check Engine" light

Just FYI, an O2 sensor code is pretty normal for Key On, Engine Running if the car isn't hot, or if it has been idling for awhile. Under those circumstances, the O2 sensors get a little lazy and stop switching, so the computer thinks it's either lean or the O2's are bad. I would say the Neutral switch code is your only problem.

-Brian

TESTING

Disconnect the O2S. Measure resistance between the sensor connector terminals PWR and GND (heater). If the reading is 2-30 ohms, the sensor's heating element is okay.

With the O2S connected and the engine running at normal operating temperature, measure voltage with DVOM between sensor connector terminals HO2S and SIG RTN. If the voltage reading is 0-1.0V at idle and 0.5-1.0V when accelerating, the sensor is okay. Also measure voltage at PWR and GND you should have batt voltage.

Make sure you have a wireing diagam so you know what wires are which. Also check them at the computer.
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