02 sensors

I had three 02 sensor codes up for the bank2 sensor2 on my Sierra. I replaced the sensor and immediately had all three come back along with the same three counterpart codes for bank1 sensor1. Does anyone have any idea what could have caused that?

post the actual codes you got. Before the repair, and now after the repair.

also tell us year & mileage of this GMC Sierra

It’s an 06 Sierra 2500hd approaching 180k miles. I had p0056 p0060 and p0161 up, which are all for bank2 sensor2 if I’m not mistaken. After I replaced the sensor those codes came back immediately except for p0060 which came back after a few start ups. Also immediately I had p0030 and p0135 for bank1 sensor1. Afterwards a third code came up for bank1 sensor1. I can’t think of those numbers right now but it was a heater resistance code. Basically the counterpart of p0060. I knew it might be a wiring issue before I started but decided to take a chance and replace the sensor. What I’m trying to understand is why changing it caused the same problems on bank1 sensor1.

Have you checked to see if the 15 amp heater fuse for the o2 sensor has blown?


I did and it looked fine. Although I have to admit I wasn’t exactly sure how to know if it’s blown.


Thanks. The visual aid is really helpful. I’ll make certain tomorrow but I’m fairly certain the fuse is good.

Fuses still intact.