Vehicle Damage Warnings
SILICONE WARNINGSilicone spray will instantly render an oxygen sensor inoperative. Do not use silicone spray near an unprotected oxygen sensor. Do not use any type of silicone lubricant or sealant on engine parts such as injector seals, throttle plates, intake or exhaust manifold gaskets, etc. as the silicone is still harmful to the oxygen sensor after combustion.
LEADED FUEL WARNING
Do not use leaded fuel in an engine even for testing purposes. The lead used in fuels will permanently damage the oxygen sensor and the catalytic converter by coating their active surfaces with lead deposits. If leaded fuel must be used in an emergency, the oxygen sensor and catalytic converter must be replaced.
CATALYTIC CONVERTER OVERHEATING
Engines should not be run for more than a couple of minutes if there are signs of misfiring or an excessively rich running condition. Tests involving shorting the ignition to individual cylinders (a cylinder balance test for example) should be kept as brief as possible, with ample time given between steps to allow the catalytic converter to cool down. Engine malfunctions, such as misfires, can cause the temperature of the converter to increase to more than 1400°C (2500°F). Such temperatures can lead to the complete destruction of the converter through the melting of the ceramic grid material.