Replaced O2Sensor -Better Mileage and Lower Oil Consumption?

[dixoncj]

So I just replaced the 02 sensor on my 91 Westy stock WBX with 160K miles. Also fixed leaks at a few exhaust gaskets, re-grounded, and installed new cap/rotor. Van is running very well. Just drove it 1000 miles and back from Charleston, SC to the Outer Banks. Thing is, it usually uses more than a quart of oil in 1000 miles. This time, it probably used 2/3 quart in the whole drive.

Is it possible that with less gasoline in the air/fuel mixture - in other words, with a properly functioning FI system that doesn't run full-rich all the time - you get less thinning of the oil through gasoline-filled blowby - and thus use less oil? Doing this - and getting better mileage too - made me realize I've probably been driving with a bad 02 sensor for some time. Living in a place with no emissions inspections, FI issues can be ignored to an unhealthy degree.