I plugged in my inexpensive code reader after getting a SES light. Not sure what I'm seeing as I roll through the menu:
DTC: 02
Fault: 01
Pend: 01

P0155 (right arrow)
01/02
P
P0155 (left arrow)
02/02

Kind of looks like Sensor 2 but isnt P0155 supposed to be S1?

 

You have two O2 sensors before the cat converter.

PO135 = bank 1 sensor 1
PO155 = bank 2 sensor 1

Read here. Please diagnose before throwing parts at it.

https://blazerforum.com/forum/diagno...plained-35155/

 

What should I make of my code, P0155 01/02 and 02/02?

 

Read the link please. All you need to know to repair your problem is there. If you still have questions after studying the link, then please go ahead and ask them.

I would assume that 1/2 would be a P0155 code that fully set and actually turned on the SES light, and 2/2 would be another P0155 code where a problem was recognized but testing was still pending when you read the codes. Note that P0155 codes once set, stay for a certain number of key cycles. Again it's in the link.

 

01/02 and 02/02 are referring to two instances of the same code, not sensor position.

 

Ahhh, thanks.

 

No prob. I finally realized that is what was confusing you. Good luck and best wishes for a successful repair.

 

I swapped the sensors and cleared the code, now I'm just waiting for the warning light to come back on. I guess this will take a couple of days. Would it go faster if l did not erase the codes?

 

Clearing the codes is the right thing to do. If the O2 sensor itself is bad, then the code will change to a PO135. If it doesn't change codes and remains a P0155, then it's something else.


If you scanner does live data you can always monitor the O2 sensors and see what is going on. Plots are best for O2 sensor voltage as they tend to cycle rapidly.

 

When I swapped sensors the code switched from P0155 to P0135. I went and a Denso new sensor, installed it and after a few days the SES light went out. However I still get a P0135 on my OBD. Should I erase and start over or will the code clear by itself.