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

[honkon]

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.

 

[L31MaxExpress]

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.

Agreed! My rear sensors are still the ones my 97 Express rolled down the assembly line with back in 1996. They are actually completely disabled now and their only purpose is visual for emissions.

 

[Supercharged111]

The only tool that ever works for me to get an O2 out is a pair of vise grips with a cheater pipe. Everything else just slips.

 

[Supercharged111]

The only tool that ever works for me to get an O2 out is a pair of vise grips with a cheater pipe. Everything else just slips.

 

[1997]

got all 4 originals of mine out on the 97 using a 22mm wrench. (IIRMC) Wasn't even a challenge. Factory SS exhaust is the cats a$$. Gm must of been made to use it. Thinking trucks local environment is the real challenge.

 

[Supercharged111]

Good point, my exhaust is completely aftermarket and not stainless.

 

[Schurkey]

My '97 has stainless steel where the O2 sensors screw in. Stainless threads are easily damaged.

https://en.wikipedia.org/wiki/Galling

 

[Supercharged111]

My '97 has stainless steel where the O2 sensors screw in. Stainless threads are easily damaged.

https://en.wikipedia.org/wiki/Galling

Yes for stainless on stainless, not so much for stainless on mild.

 

[PlayingWithTBI]

Yes for stainless on stainless, not so much for stainless on mild.

When I worked at a food processing plant we used Fastenal SS hardware. They would gall up almost every time if you didn't use anti-seize. We switched to Lawson products and didn't have any problems. The way it was explained to me, Lawson used 2 different alloys in their SS hardware.

 

[Supercharged111]

I wonder if the Lawson was just a different grade of stainless vs Fastenal? Sounds like it. I thought I'd be smart with my stainless header and use stainless bolts on the 2-1 coming off of the 4-2. It galled and I was told to use mild hardware, never had a problem since.