1995 Camry White Smoke out exhaust
 

1995 Camry V6 le runs great 215000. No error lights. No leaks.

Some mornings there is a large puff of white clean smoke and goes away after a minute.

Has no smell to it.

No oil residue on exhaust

Never changed cats or oxidation sensors, just rear muffler recently with one from junkyard.

Burns some oil but not unusual.

Concerned its a sensor or cat.

Original cats

A few questions:

Thin or thick smoke?
Does the Smoke occur on a cold morning, warm morning or the temp makes no difference?
On most mornings is there no smoke?
Is there smoke after sitting overnight or even just sitting a few hours, etc.
Was there no smoke before exhaust system work?
Did the smoke suddenly appear or gradually get worse over time?
Was the engine ever overheated or the temp gauge get into the red?

Smell the smoke for oil (typically valve stem seals), fuel (injector issues) or sweet (coolant). Put a paper towel on the exhaust pipe to filter the smoke and catch debris. Feel the paper towel if oily, slick (coolant) or just water.

A CAT is not going to cause smoke but the smoke could damage the CAT.

Weather does not appear to change it but it kind of appears to happen more under rainy , foggy conditions.

Bright white dense smoke.

Most mornings no smoke.

No smoke before exhaust work.

Smoke appears as a small cloud and has no smell (stuck my head in the small cloud) and then goes away. Never seen while driving on highway or city. Just when start.

Appearing a little more often on start.

Will take your suggestion and filter the exhaust with a paper towel and see what comes up.

One thing that has changed
Purchased a new radiator cap since the old ones seal was leaking 2 months ago.
The OEM one I put on was super tight, very hard to put on and left it as is.
Just pulled it off now and put one on I bought at Autozone thinking the cap was the issue. 10/09/18
Also replaced the antifreeze reservoir tank with an oem. It was leaking. 2 months ago

Feel and smell the coolant (a now mix of antifreeze and water) in the reservoir. Then compare to what ends up on the paper towel.

It has happened the valve stem seals harden up with age. This results in a nice cloud of white smoke at overnight morning engine start up. Typically this smoke issue gets worse with time.

None of the smoke issues listed here are going to be showing up when driving unless there is a major engine coolant engine internal leak, major blowby, etc. The engine and perhaps exhaust system (condensation) is cleaning itself out in the morning from accumulated overnight debris.

Thanks so much. Will keep you posted.

So far no smoke issues at all. I did forget to add this car went from a locally driven car 100 miles or so a week to my daily driver 400 miles a week mostly highway. I have a new car and trying to lessen the mileage on that one that is used for local and college trips across the country.

Perhaps more driving is keeping the engine cleaned out.

Makes sense . Thanks.

The smoke returned some when weather warmed up and check engine light appeared..

P0401 egr valve flow insufficient detected.. Never changed.EGR.

Maybe this is the problem. Buying an EGR.

Maybe I