I have a 2002 Camry LE, it has 154k miles on it, we love it. We have had no problems. Just recently when the car sits over night, and only during the first start up, the car throws out white smoke. One big puff. Any ideas? I hoping that this is not that serious.

 

Most likely the valve stem seals are wearing out. The length of puff will most likely increase with more miles.

It is possible but very time consuming to replace the seals with the head still on the block.

One issue is over time the catalytic converter may fail due this ongoing oil pollution.

 

You probably have a blown gasket, have it replaced before the problem deepens. The 2.2 liter engine on the 1997-2002 year model is known for blowing gaskets right around the mileage you have on your vehicle. It's not an expensive repair and you might be able to do it yourself.