2003 4Runner V8 Code P0430

[brhoward]

Placed my 4Runner on a computer and it said Catilist Effeciency Below Threshold Bank 2.

The Enging Light VSC/Trac Control light have been on for some time. I went to Colorado and for the entire time there or about 1600 miles of driving around Colorado I never had any of the lights on. Then when I came back to Okla it came back on. Does this sound like the O2 sensor or like the Catalytic Converter? I have about 90K on my 4Runner at this time and the sensors have never been changed. I just figured since the lights were off for the week in Colorado that maybe that narrowed it down to the O2 sensor. Help Please!!!! Thanks

[RobXS]

Probably the sensor going bad. The higher altitude or the lower octane gas probably made the difference. You may also want to clean the MAF first. It could be dirty and causing it to run a little rich.