I had diagnostics run on my 2004 Jeep Grand Cherokee today and was told it's my O2 sensor, already figured that! It's Bank 1 Sensor 2- is that cylinder 4 5 and 6, post catalytic converter?

Cylinders 1,3,5 after cat

Bank 1 is the right hand bank looking at the rngine from the front on a convention car or the bank closest to the fire wall on an east west set up
o2 sensors are always after the cat converter
HO2S or heated oxygen sensor which are different to O2 sensors are always in the exhaust manifold or pipe before the cat converter

Be nice to post the code, not decode then and say.
and which engine. ?
p0141, bad heater or the other error. see why we ask.??????
p0136 to 140,, amazing, its not just one error for 1/2 sensor.
and p017x.?



B1S1 fails. and no other codes,?????
bad sensor
bad wires to sensor.
exhaust leaks near any 02 sensor makes it, lie.
air is 20% oxygen ! HUGE, and if that hits the sensor tip, bam it lies.
even on new sensors ,

click WJ here
then emission c25. behold.


http://www.morris4x4center.com/knowledge-base/index.htm?utm_source=cj#service

100% free to read, and is the real book, no bs