hi babyhuey and keninn,
I just noticed white smoke like for 10 sec outta tail pipe. Does this solve the mystry of having P431 and P421 cat codes? I hope you remember my post about both cats goin bad ( which is quite rare). I think its this white smoke that is causing a problem(s) in catsand O2 sensors . I have browsed forum for the causes of white smoke and it looks like either supercharger is bad or oil seals have worn. Any advice would be helpful.
Thanks in advance!

 

are you sure it is smoke and not STEAM?

 

i dont think it's a solution. it could just be condensation that has settled in the exhaust after shutdown. white would be water/coolant. try go back and take a whiff of it, you can smell oil and coolant.

 

White smoke & sweet smell = coolant
Blue smoke = oil
Black smoke = fuel

 

I checked this morning again. Its not even 10 sec ( started the car and rantosee the tail) probably3 sec and its hard to tell dat smoke is blue or white because its not that dense . I smelled the smoke, nothing.May beI was just smelling air beacuseI hadnt had enough time to catch the smoke. I touched the tail pipe from inside to see any oil ( or carbon ) deposites..nothing. I don't know if something is wrong orI am just worrying about somethin which is not even there.
I do get cats code once in a while ( first P421 andifI dont clear itI would get P431 later; two codes). Had O2 sensors changed but problem didnt go away. I dont see any performance problem with the car and local mechanics also agreed that cats look fine and they are doing there job ( thats what their scanner showed everytime they checked it). I thought I nailed down the problem by identifying smoke..lol but looks like I didnt.