I was looking at the 'engine data' in FreeScan and noticed that my 02 Volts L change constantly between 0.879 to 0.901 while my 02 Volts R = 0.448 constantly and never changes. Could this mean my right 02 is bad? The SES light doesn't come on and there are no codes stored. Any ideas? This is on a '95 T/A btw

Thanks in advance!

 

You need to look at the O2 volts in both closed loop and in power enrichment. In either case, if the right sensor voltage is staying fixed at 0.448 V, there's a good chance it is either toasted or disconnected. What you are seeing is the voltage the PCM supplies to the sensor. Odd that it hasn't set a code.

When you start the engine cold, look at both sensors. They should start around 450mV, and then drop over a couple minutes into the 00x mV range. That tells the PCM the sensor is warmed up and ready to go.. and it enters closed loop. Then they should start to fluctuate rapidly between 0xx and 9xx mV's. If you have no activity on the right side, you have a problem.