I've searched and wasn't able to come up with what I am looking for.

I tested my primary 02 sensor in my evo 8 mr ( the one in the 02 housing ) and it was only reading 0.60 to 0. 64 quickly then returning back to 0.60.

This was done with the car off and cold.

Does anybody know what it is suppose to readies?

Have been getting about 100 miles to the tank and can't figure out why.

Cleaned the MAF, ran seafoam, fuel injector cleaner.

Help?

 

Test the O2 sensor output voltage when the engine is running and fully warmed up. The output voltage should fluctuate at idle around a mid point of 0.6V anywhere between 0 and 1V. When you rev the engine you should see the output increase temporarily to above 0.6V which indicates a rich mixture. When you stop revving the voltage should return to fluctuating around the mid point of 0.6V.

If the sensor output voltage does not change at all then it has failed. If the output voltage changes but only sluggishly then the sensor has aged and should be replaced.