I ran the codes to try to figure out the check engine light and got a p0155 (bank 2 sensor 1 02 trouble). I replaced the 02 sensor (drivers side upstream of the cat) and after resetting the computer, got the check engine light again. (after about 20 mins of driving). I am still getting the same p0155code as the trouble. Is there anything else to check. i was careful not to let anything touch the probe prior to install so i feel it was put in correctly. any suggestions would be really helpful. thanks.

 

Seems you totally missed the intent of the 155 code.
It's the heater circuit in trouble for that sensor.
Many code charts don't give enough info and leads people astray.
Changing the sensor when there is a power problem to it, won't fix it.
There is a wire or connector plug problem causing no power to the heating element for just that side.
Time to get a voltmeter out and do some checks and take a look at the harness.
It's a 4 wire device so 'donot' try to measure resistance of the OX sensor half of the device it'self.
Once the engine fully warms, you won't see any running effects from it but the PCM know's there is a problem because it monitors all these functions by design.
Good luck.

 

Bluegrass, thanks alot. that makes sense with the readout on the data link. It stated "heater ckt control malfunction". Now the problem, any thoughts on where to look for the break? From the wiring diagrams it looks as if all the heater ckts tie in together prior to the PCM. If this is the only faulty one, it should be between the o2 sensor and the next junction. Does that make sense? Thanks again for the help.

 

That is a good bet.
If you have to test at the PCM, pins 93 thru 96 are the heater voltage monitors for all the 02 sensors.
Check for missing voltage or a lead that does not measure like the other 3 in a compare test.
Could even be an individul ground.

 

got it, i'll get to working on it. i appreciate the help. thanks