I think that rule has changed. The 1975 is the last year that will be smog exempt for the forseable future.

-Andy

BBAY1,

Good advice above. I suspect the PO overfilled the oil, some may (or may not) have gotten in the intake. While sitting the large amount of oil drained back into the crankcase and filled above the level of the bottom of the cylinders and leaked past the rings. It can also leak past worn exhaust valve seals.

When the engine fired, it pumped a lot of oil into the cat and muffler. This is why it starts to smoke after some driving – the muffler finally gets hot enough to burn the oil off.

The best solution is to have a radiator shop “boil out” the muffler. The cat probably will clean out as the 911 is driven at temperature. You can’t know until you try. At worst the cat might need replacing if you need.

Checking inside the intake plenum (difficult) is the only way to tell if oil is there. If there is some, it will eventually work its way through the engine.

Best,
Grady