Who has cheap 740 O2 sensor?

Its for my 92 740 turbo wagon. After changing the air mass meter, the
gas mileage went up to normal for a couple of weeks, and then
plummeted again. Needs another new part. Rock Auto has a Bosch sensor
for $99. But I seem to remember a few months ago someone in this forum
told me of a source for one that is only around $ 60. The car is
setting a code for "adaptive lambda either too rich or too lean at
part load". It is 3-wire , heated type.

 

There are "universal" sensors sold for around $60 which require splicing
instead of being a direct plug in. I've not had the best of luck with
those splices and would spend the extra $40 (about one tank of fuel!) to
get a direct connect type.

 

Part of my job as an avionics tech is making high-reliablility
splices, so I have no qualms about tackling automotive splices. Its
the mechanic stuff I am often not so hot with ;-) Regards, Geronimo.

 

Test your lambda first, because the most certain is
that the problem should be elsewhere.

You need a multimeter and a gas flame and some instructions
that you can find in the web, like I did some years ago.

 

Yea, I probably should look at the connector first...its is in
such a high-heat area, and the car is so old.....still the O2 sensor
has probably not been changed well in excess of 60K miles, I suspect.
I was looking at a NTK brand universal replacement. THe salesman on
the i-net whom I chatted with said it is not a good idea to get a
universal (no connector) as I will "never get a good enough
connection, and the reading will be inaccurate". What does teh
average mechanic do? Crimp a plain butt splice on?
He may be right...but it depends on how long the wires are a lot,
the splices will get hot as an oven if the wires are only a few inches
long! Possibly it would get so hot with the splices near the sensor
that even a normally high reliability splice like a solder-splice with
(high-temp fusion wrap) would melt or weaken.
I can pay $65 for a NTK universal, or for *$100 MORE* get the very
same thing with a connector! Thats' insane.