Tracker 2WD L4-2.0L VIN C (1999)
be introduced through the fuel system or can be airborne. Some of the contaminants that may be encountered are phosphorus, lead, silica, and sulfur. One
of the more common contaminants is silica in the form of silicone. Silicone contamination may be indicated by a white powdery deposit on the portion of
the HO2S that is exposed to the exhaust stream. Silicone contamination can be caused by the use of gasoline with silicone in it or by the use of RTV
sealants which emit silicone into the crankcase or induction system. Oxygen sensors exposed to high concentrations of engine coolant or engine oil in the
exhaust stream can also be adversely affected.
The fuel control heated oxygen sensor (HO2S 1) is diagnosed for the following conditions:
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A slow response
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An inactive signal (output steady)
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A signal fixed high
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A signal fixed low
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The heater performance
