Hey Scotty,
I have a 1999 Chevy Silverado 1500 standard cab, long bed, 4.3 V6, manual trans, with 274K miles that I am putting back on the road after 7 years in storage. I had rebuilt the transmission and had a valve job done to fix some oil consumption issues. After getting it back together, I had the codes for both of the post cat O2 sensors heating element (PO141 and PO161). I installed new sensors and cleared the codes, but they came back after driving it around for awhile before I could get it smog certified for registration (it is on a temporary operating permit). The local shop scanned it and weren't able to determine the problem, speculated that it may need a software/firmware update and referred me to the dealer. I have an appointment for next Monday, but I was wondering if you have any advice on correcting this before I have to shell out dealer service fees.
Thanks,
Mike
Has the simple step of checking for 12V across the heaters of the O2 sensors been done?
https://www.carparts.com/blog/p0141-code-oxygen-sensor-heater-circuit-malfunction-bank-1-sensor-2/
12 volts present at the sensor, ground is verified, sensor ohm checked out.
12 volts present at the sensor, ground is verified, sensor ohm checked out.
If that's the case the heaters should be working properly. Does live data show current being drawn? Are the new O2 sensors OEM or aftermarket?
It's also possible that you're seeing spurious codes being thrown due to another problem affecting the electrical system.
Taking a nearly 25-year-old vehicle to a dealer would likely be an expensive and frustrating experience. Many of the technicians there would not even have been born yet when that truck was built.
graph your O2 sensor data
After disconnecting and probing all the circuits, then reconnecting the sensors, the code went away. Electrical gremlins are so fun the chase...