Follow up to Original 'Puff of blue smoke at start up post'

Just wanted to share what I've learned or at least observed since my original post.

No more blue smoke at start up and I still haven't replaced the PCV valve.

I had mentioned in my original post I added a can of

$25 BG44K BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44K prior to noticing the blue smoke. I've used this product for a long time in several vehicles and never had anything come out of the exhaust from it. Well after I fill up after the tank with the BG44K in it, I noticed the blue puff one more time. After that I have not seen it again. Did the BG44K cause it? I really don't know, but maybe. Or it's since warmed up considerably here with non freezing temps at night, the blue smoke was visible on those below freezing mornings. Was it the cold weather or the combination of the cold and BG44K? I don't know, but I'm a little more at ease with no puff for now!

Thanks again everyone for all the information and advice. I will eventually get the PCV replaced, because it's cheap and for more peace of mind!