Toyota Rav4 problem?

[In The Rat Race]

I have a rav4 2000 2.0L VVTI with 67k miles. I have had a diagnostics done and that shows that I need to replace 3 of the 4 oxygen sensors, which I have not done yet. Apart from that, my question is about the white smoke I get from the exhaust pipe even when the engine is at normal operating temp. any ideas what this could be. many thanks!

 

[oli c]

white or a hint of grey, the oxygen sensors {lambda} trim the fuel they can make it run lean and they can make it run rich, if it is runnig rich you will get some grey haze, maybe even smoke if they are that far gone