The O2 sensor was replaced last August. Here are all the results from the test:

High speed @ 2574RPM
Standard Current reading result

HC 220 137 pass
CO 1.2 .50 pass
CO2 14.5 n/a


Low speed @668RPM

Standard Current reading result

HC 220 390 fail
CO 1.2 .64 pass
CO2 14.3 n/a


Anyhow, the engine is running good. The plugs cap and wires are all good, air filter new. Uses about a quart of oil every 3000 miles. I'm inclined to believe what Steve said which was that I need a new cat. Should I go for new pre-cats and center cat as well when I do the change?

Thanks.