Originally posted by TVR383
The engine,for undetermined reasons yet, consume oil at the rate of about 1/2 quart for 700 miles...could this influence the fuel mixture and the O2 sensor readings?
If you're motor is consuming that much oil you must be blowing a huge cloud of blue smoke out the exhaust everywhere you go. I suspect your probably leaking oil somewhere rather than burning that much but yes if you are burning a lot of oil it may effect your oxygen sensor and will probably effect your fuel mixture readings as well.
Does the sensor read rich just at idle or at all RPMs? If just at idle try changing your step rod springs. Carter and Holley make idle step rod spring sets with different tension springs for varying engine idle vacuum conditions. If you're running a big cam then chances are your springs are too heavy and you're feeding the engine too much fuel at idle.