My first question is also "why?" I presume you had a check engine light and the code implicated the oxygen sensor, but you should know the cause of nearly all "Heated O2 [HO2S]" codes is in the heater control. If you tell us which code(s) led you to change the sensor it will clear up a lot.
Rich mixtures don't damage O2 sensors without the check engine light being on a very long time, but Wondering is absolutely correct - even traces of silicone will ruin an O2 sensor very quickly indeed and without the engine light until it is too late. If you have had the car detailed recently and they made the inside of the engine compartment gleam, you can be sure they sprayed it with silicone. The air filter element must be replaced in that case or it can poison a lot of O2 sensors.
The Toyota mixture control is very conventional and the parts are standard. The trolls who suggest these are somehow uniquely Toyota defects are not *that* ignorant - they are just being trolls.
www.ehow.com
I have replaced 3 freaking Oxygen sensors in 1 year?
Linear Mode
