Oxygen Sensor or PCM Issue?

[rgg]

I have a 2005 Silverado Z71 5.3L B with over 100K miles. Last month getting Check Engine light, so invested in a cheap scanner. Code P0053 (Sensor 1 Bank 1). Replaced the sensor and received the P0053 code. Visually checked connections, etc. So, figured that I would switch new sensor 1 with real old sensor 1 bank 2 (expecting the code to move to bank 2). Received code P0153. So, switched sensors back and replaced bank 2 (no need but since I was getting good at replacing it).

Connector 1 and 2 (bank 1 and 2) checked for short to ground conditions both the same (c & d had ohms and a & b infinity) which is what I expected (I think). Performed short to voltage on both connectors resulting in 0 volts on all legs except pin D which is what I would expect since it looks like pin / wire D is on the fuse side. Turn key on and probed again and 12 volts on pin D again what I would expect. So now, drive the truck few days ago ambient temp was 80 and no check engine light. Next day, ambient temp 91 turned key on and check engine light stayed on (never went out). Same code of P0053 again. Any suggestions? It seems as though temp is in the mix on start up as the light didn't come on, it was already on (didn't reset)..

 

Any help would be appreciated.

[rgg]

I guess I've stumped the experts?

[Carder09]

Either way, its about time for.some new sensors. Seems a few people have had this issue before and replaced the sensors and say.that over all performance and mileàge increased.

[rgg]

Replaced sensor 3 x. Problem solved replaced the rear not front (could not see) by accident. Replaced front and all is well.