[33k!]

I have been getting poor MPG for a while and so I replaced the AF and oxygen sensors.

My MPG problem did not stop, so now I suspect the catalytic converters.
I warmed up the engine and took sensor readings with techstream.

At idle, my AF sensors read a steady 3.29v but my oxygen sensors are reading 0.76v. I have read that the oxygen sensors should read 0.45v.

Does this mean my cat is bad? I have a 2GR-FE V6 with 170,000 miles and I get 16-19 mpg with a loss of power.

 

[ordpete944]

I noticed a big difference in power when i replaced my cats at 140000 miles in my 4 cylinder. The power loss was gradual do i didn't really notice it until i fixed the restriction. Make sure your engine is breathing well on the intake side by checking the air filter. If you haven't done the in - tank fuel filter, It probably wouldn't hurt with your high mileage.

Are you getting the rotten egg smell when you floor it? It is easier to detect with your vent system on recirculate. That went away when i replaced the cats.

Catalytic Converter

This website has some good information regarding a faulty catalytic converter.