New to this forum, I am a regular at tacomaworld.com among a few others...

My sister in law has a problem though. ... and I figure you and me and this forum.......... We're gonna kick this little problems ***.

So,

02 Blazer, 130k. Getting an 02 sensor check engine light. Code says Bank 2 Sensor 1. The catalytic converter has already been replaced. She was told by a shop that the 02 sensor failure caused it. It was bogged down and couldn't even be driven before the cat was replaced. I'm getting mixed information while searching. So, I'm gonna ask you directly.

I've searched and found reccomended to swap "side to side" the sensors to illiminate electrical wiring issues as a possibility. Honestly I'm not sure exactly what that means. I was planning on just replacing bk 2 sensor 1. Anyone have a great link to a diy on that?

I have the part (I doubt it's the ac delco one that's usually recomended. Prolly that ol' bosh buddy of yours, she purchased it today) Reguardless, I think she'll (have me) sell the car after it's running well. So the part lasting isn't that big a deal. ....for her anyway.


Thoughts?

 

one of the two front sensors is bad. im dont remember wich one is which, i clear codes and unplug one and run a few minutes, then pull the pending codes to see if i have the right sensor. a bad sensor can hurt the cat but it was most likley damaged when being handled when the pipe was serviced, dont be mad there delicate and im sure they have been in there longer than they should of, 75k service interval. bosch is ok on this one, all 3 sensors are the same exactly, just need a 7/8'' wrench and a pair of gloves helps lol. have seen rear sensor plug get rotten on these but not either of the front sensors. u have 3 total. good luck

 

Had a very similar problem with mine.
First, the engine light came on with a code of 1055 Bank 2 sensor 1. I replaced that, cleared the code, drove roughly 50 miles and the same code came up again.
Next, I decided to switch the sensor with the other one on the drivers side to see if it would follow the code. It did so I figured it was a bum sensor and replaced the sensor, hoping it wasn't a wiring problem. So next a cleared the code drove another 50miles and the other code (1035 ) came up.
Would appreciate any help on this, ran out of ideas and wondering if I may have a wiring issue/where to test
Also there is 73,000 mi on the truck and they were original sensors before the change.
Thanks

 

Yaxta, I'm thinking you have things out of order in your P-code number. P0155 is the B2S1 sensor (passenger side is B2). P0135 is the B1S1 sensor. Since the code followed the sensor, the problem is with the sensor and you got a bad replacement. If it wasn't an AC Delco, return it and get your money back, then buy an AC Delco sensor. In my direct experiments with various aftermarket sensor manufacturers in GM applications, the only one to come close to AC Delco's out of the box activity is NGK who I believe makes AC Delco's sensors, but don't have anything to back that up with...

To Salem, what was the specific code? Different codes mean different things and have different troubleshooting steps.

 

hi new to this but hope you can help when the check engin light came on i brought it to auto zone so they could pull the codes they said two codes showed up and he said both upstream sensors need to be replaced . Do they both go bad at the same time or he just trying to make a sale?