I found the front O2 sensor at Advance Auto Parts for $56
(less $20 with a promotion code: "RETMENOT123"
when you order online, or $36 + state tax. Order it online and pick it up at the local
store minutes later at the heavily discounted price. Not bad compared to $115 elsewhere
Bosch Premium Oxygen Sensor with OE SmartLink part 15727

SmartLink is a solderless 4-pole connector to reuse the old wiring harness.

From the Bosch installation guide:
> "Do NOT cut wires while removing the existing sensor from the vehicle."
> "Do NOT solder wires. Soldering wires will lead to early sensor failure."

First- I'd like to snip the old harness off at the sensor so I can use an ordinary socket.
Second- What's wrong with soldering? I have a basic mistrust of solderless connections.

As an aside, it was an adventure dealing with Advance's website and required
a phone call to their Texas service center to open an account, and afterwards
it was tricky to get the site to go through it's operations because of
a number of parasite operations present that were NOT allowed by my browser.

llnwd.net
liveperson.net
google.com
coremetrics.com
channelintelligence.com

I use Linux and a Mozilla Browser with the "Noscript" addon that reported all this
extra baggage. AAAK! Does Google participate in every internet transaction?!
I suppose the $20 heavy discount is the incentive to get datamined.

Bill

I replaced both of mine with universal sensors. They both came with a special crimp connector and both warned not to solder the connections. Don't really know the reason why although there may be some odd resistance possibly created somehow with certain solder. I tried some standard O2 sensor sockets and none worked. I resorted to crushing the old O2 sensor with some Visgrips and pulling off the can so that a 7/8 socket wrench would fit.

Hiya Fixit!

Did you see any mileage improvement with the new O2 sensors?

The new O2 sensor is in, but what a PIA, I found a 7/8 box wrench needed
a longer handle and nothing seemed to fit, so I took a short length of 1-1/4"
pipe and smashed the end 3" down so that the open end part of the wrench fit tight
and that worked (after heating the thing for several minutes with a propane torch.
My MAPP gas decided to run out when I needed it most!
Maybe it's easier to saw the sensor with a sawzall and take it out with a 1/2 drive 7/8" socket and a 2' breaker bar? It was really stuck in there.

Then the miserable thing came out with what looked like the threads all galled up.
So I borrowed a 18MM-1.5 tap to clean the down pipe thread. and now I'm back in
business. Now if the solderless connector doesn't fall apart I'll be happy.

Bill

Did some polking around in Google and found that some senors have "reference" air that supposedly travels down the strands of the connector wire and that's why you can't solder the wires??? Seems sort of fishy to me but that's what Bosch says??? Maybe it's just to make you buy the whole sensor and not try to adapt a cheaper version? Who knows but there's lot of different opinions.

I read that "story" also. It doesn't sound reasonable to me.

That's why it's good to exchange notes with other techs.

LOL, there is no "air" in the sensor wiring. What a bunch of junk. What is plausable it that people could use the wrong strength of solder and increase the resistance.

Klaus
--
There is no present time, just the past and future

Hiya Klaus

Copper has less resistance than solder, but the difference of a soldered joint is so tiny as to be hard to measure. Just adding a little length to the harness will get you more resistance. Sounds like that story came from some car salesman.

My my around town mileage before the new front O2 sensor was 14.7
Ach! I hope it's because the old sensor was gonzo and not because of
crappy ethanol fuel!

I know that in boats, they dont like solder because it can break under vibration. crimped screw terminals seem to hold up better under vibration.