bad o2 sensor ?

o2 sensors, like spark plugs, get tired with age and are recommended to be changed out at about 100k miles. You likely have 3 o2 sensors, two before the cat & one after the cat. While the right side o2 sensor could be at fault, more likely there is an issue before the sensors that are causing the code. Dirty MAF and/or MAP sensors, leaking fuel injector, dirty air filter, etc... causing an improper fuel mixture & tossing a code.

If the sensors are near the end of their usable life, replace'em, but most likely they are telling the computer something ain't right upstream.

B1S1 - Bank 1 Sensor 1 which is the driver's side fuel management O2 sensor located on the driver's side of the y-pipe a few inches down from the exhaust manifold.

B2S1 - Bank 2 Sensor 1 which is the passenger's side fuel management O2 sensor located directly ahead of where the 'Y' is on the y-pipe.

B1S2 - Bank 1 Sensor 2 which is the catalyst monitoring O2 sensor which is located behind the catalytic converter. (could be B1S3 on the 98-2000's)

Also, there is a fuse for the o2 sensors, check that. It does sound like the heated element is out on one of the bank 1 sensors.

Did you erase the code and turn the CEL off with a scan tool?

Driver side before the converter.

https://www.troublecodes.net/pcodes/p0135/

I replaced the one on the drivers side before the cat ! that was the only one I saw on the drivers side ! I saw 2 on the passenger side ! one before the cat and one after ! the code reader reads po135 oxygen sensor heater on bank one ! not too long ago I replaced one on the drivers side but the light still comes on after I clear the codes !

Your V6 will have 4 sensors, 2 on each side. Recheck the code: bank 1 sensor 1 is the one near the exhaust manifold, bank 1 sensor 2 will be after the catalytic converter under the vehicle. Which one did you replace? If it is not seated properly or if you have an exhaust leak near the sensor you will get the code even with a new sensor.