Hi, I've a silverado 2003 5.3L, my truck is coding p0135...and one time it appears the p0134 but never see it again after 200 miles...
I put a new oem o2 sensor but still coding. I took the left and put it too the right side and still coding...The truck is idling fine and run great...
I checked the live data stream and the o2 sensor is passing from .0500 volt to .800 volt , with peak from 0.050 to .950 volt...the data is fluctuating a lot
if the refer to the other upstream o2 sensor...Can somebody help me to solve my problem..?? thanks!

 

check the 02 heater fuses.

 

They are ok...I forgot to mension...

 

test with the exhaust stream cold.
disconnect the 02 sensor connector. check for battery voltage on the pink wire with the koeo = key on in run engine off.
if that is ok, put a test light between the pink wire and black/white wire. turn the key koeo...the test light should blink on and off

 

I got 12v between C and D...how come its suppose to blink with a test light?

 

the dtc is set due to a fault with the heater circuit. the other dtc that set from the 02 not responding quickly enough from the sensor not reaching temp is a predetermined amount of time. fix the heater circuit dtc and you fix the p0134

the pcm pulse width modulates the heater on and off. Its low driver controlled so the grd is turned on and off, power is supplied at all times by the fused circuit that you have checked.

You must test this with a test light as you must simulate a load...a dvom does not do that.

 

Ok I will check that...but I'm thinking maybe it's a bad Ho2 ground?? I will do more test wednesday.
by the way, when the truck is running (cold start) the o2 sensor readout is: o2 sensor bank1 sesnsor1 = 0.545V o2 bank2 sensor1 =0.070V

 

the fault is not with the sensor part of the 02 so those readings are irrelevant. the pcm puts out a bias voltage of 0.5volts untill the sensor heats up and starts working. the rear 02 will not switch like a front 02 as its after the convertor.