2004 Yukon o2 sensor error codes again

[wilddog54]

Hi, I have a 2004 Yukon, about a year ago I kept getting error codes saying the o2 sensors were bad so I replaced the ones it said, then a while later I got more error codes on the ones I didn't replace. so I replaced those. Then codes popped up on a couple of the first ones I replaced so I did all 4 of them this time. It was fine for a long time, few months, but now the codes are back again. I get P0141, P0155,P0111 and also code P0302 that says theres a miss on #2 cylinder which is new. My question is I don't believe these sensors keep going bad, and I'm wondering if something else can be setting these codes and making it look like the o2 sensors. I mean 3 going bad that fast is hard to believe. Any ideas are appreciated.

 

[HiHoeSilver]

Hi, I have a 2004 Yukon, about a year ago I kept getting error codes saying the o2 sensors were bad so I replaced the ones it said, then a while later I got more error codes on the ones I didn't replace. so I replaced those. Then codes popped up on a couple of the first ones I replaced so I did all 4 of them this time. It was fine for a long time, few months, but now the codes are back again. I get P0141, P0155,P0111 and also code P0302 that says theres a miss on #2 cylinder which is new. My question is I don't believe these sensors keep going bad, and I'm wondering if something else can be setting these codes and making it look like the o2 sensors. I mean 3 going bad that fast is hard to believe. Any ideas are appreciated.

Check the harnesses for the sensors. You show B1S2 & B2S1. The 111 is the IAC circuit and may be related to the misfire. I'm guessing your problem is electrical.

 

[wilddog54]

Check the harnesses for the sensors. You show B1S2 & B2S1. The 111 is the IAC circuit and may be related to the misfire. I'm guessing your problem is electrical.

Good idea. I was going to check the Intake Air Temp sensor, but I can't find it. Where is it located? I suppose I could just replace it and see if that makes a difference.

 

[SnowDrifter]

If memory serves its included with the maf assembly