only found 2 O2 sensors on exhaust. replaced both and still getting p0140 error code? Does canadian trucks only have 2 sensors?
Have 2001 GMC sierra with 5.3 engine and it was made canada. I have checked and on 2001 GMC Sierra 1500
apparently someone has emptied out your catylic converters. That's why you can't clear the code.
You'll have 4 sensors total. 2 before (upstream) the catalytic converters and 2 after (downstream.) Another site said it was the MAF...Do some more homework.
This code sounds like it's indicating the second sensor on bank one.