Replacing o2 sensors ... wide range in $$$, worth paying up?

[PlayingWithTBI]

I wonder if the Lawson was just a different grade of stainless vs Fastenal?

Lawson is definitely better quality than Fastenal but, the Lawson Dude said they used different alloys to prevent this.

 

[stutaeng]

Seconded on the AC Delco o2s on Rockauto. Cheaper than many aftermarket sensors.
I don't see any point in replacing the downstream o2s out of precaution. Their only purpose is catalyst monitoring. They don't affect performance or efficiency at all. They work till they don't,
I could see it maybe if you're replacing the exhaust, but if you don't have any codes I say leave them be.
The upstream o2s are different of course. They affect fuel trims.

That's what I thought also on the lower O2 sensors.

I had P0174 constant and intermittent P0151. I was stubborn that I had a vacuum leak, but finally concluded that I didn't after checking with vaccum gauge. I checked the lowers with voltmeter and it seemed to be around the 0.5V, which is what it's supposed to be. I replaced the uppers and the P0174 went away, but still had the P0151. After I replaced the lower, the code went away.

 

[DOGFACE]

Seconded on the AC Delco o2s on Rockauto. Cheaper than many aftermarket sensors.
I don't see any point in replacing the downstream o2s out of precaution. Their only purpose is catalyst monitoring. They don't affect performance or efficiency at all. They work till they don't,
I could see it maybe if you're replacing the exhaust, but if you don't have any codes I say leave them be.
The upstream o2s are different of course. They affect fuel trims.

The first time the idiot light came on, I threw codes for three 02 sensors.

The second time the code came on, I had the mechanic who services our patrol vehicles look over the Yukon (he has serviced multiple generations of our Tahoes). He stated everything looked solid, and also noted the front end had been completely rebuilt recently and was solid (winning!!!). He noted that the vehicle was now throwing a code for Bank 1, Sensor 2) O2 sensor and EGR PCM.

I just changed out three of the sensors. I didn't screw with Bank 2, Sensor 2... the connector is enclosed in a steel box on the frame and coated with frame preserver... I'll worry about it when the time comes and/or let the poor ******* who replaces my exhaust f**k with it.

I picked up an offset 02 sensor socket from Harbor Freight, cost me $8. https://www.harborfreight.com/3-8-eighth-inch-offset-oxygen-sensor-wrench-97177.html

I had no issues removing the O2 sensors. I had to use a breaker bar on bank 1, sensor 2. I removed the EGR valve and cleaned it out with carb cleaner and reinstalled with a fresh gasket. I noted that the 02 sensors that I removed seemed to be of a lower quality than the AC Delco units that I installed.

I clearly observed a pick-up in performance, and a much smoother idle afterward. I will hade the codes reset tomorrow on the way into work. Fingers crossed that cleaning out the EGR valve did the trick!

 

[Schurkey]

I picked up an offset 02 sensor socket from Harbor Freight, cost me $8. https://www.harborfreight.com/3-8-eighth-inch-offset-oxygen-sensor-wrench-97177.html

The "real" versions of that tool are double-sided--there's a hex on both ends of the socket instead of just one.

 

[DOGFACE]

The "real" versions of that tool are double-sided--there's a hex on both ends of the socket instead of just one.

"Real" version of not, it worked fine for my application. For $8, I have zero complaints.