The books suggest replacing oxygen sensor every 30K miles.

Well, I guess that makes my oxygen sensor a senior citizen.

1990 Volvo 240 DL Wagon (140K)

But, man, a new sensor is expensive!!

What about the universal type ? Should I get one of those and get same performance?

Thanks.

Hey Survivor, ( i survived twice, hence the email name)

Any how, the post from Southern Fried Volvo is 100% accurate..I had the identical experience with my 91 240. The 3 wire universal is $39 at auto zone with a 90 warranty.

btw, i did not want to run 3 new wires from under the hood down to the new O2 sensor. While at Auto Zone, I had them look up the part number stamped on the plastic connector which came with the new O2 sensor. Turns out it is a Ford/Mercury connector that came on certain year taurus, cougar, etc...So, I went to the junk yard and pulled a couple of those connectors (no charge). After ensuring my new universal O2 sensor mated up with the ford connector (and it was the perfect fit) I then proceeded to cut off the old O2 sensor and solder the junkyard ford connector to the three wires. This provided me with a convenient socket under the car. Makes it a whole lot easier to pull the O2 sensor without having to twist and untwist the 3 wires when unscrewing the sensor!

The sensor works fine and never had another problem since..got about an extra 1/2 to 1 mpg too.

also, i soldered the 3 wires, double shrink-wrapped each connection, put some plastic flex wire conduit around the area and taped it closed. Sorta like micro surgery on a patient that can't sue ya.

good luck


mm49

I don't think the 30,000 mile replacement applies to systems with the newer 3-wire Oxygen sensors. That is why the "change sensor " light was removed. The Bentley shows replacement at 30,000 miles for 1983-1984NA. Yes, the three wire sensors are expensive. The two extra wires are for the heater in the sensor which makes it come upo to operating temperature sooner, I guess. There has been some discussion on the BB about substituting one wire universal sensors successfully. Maybe a search of the archives would turn up some information.

RE My 1985 245 After I saw what the called for 3 wire O2 sensor cost , I thought I better experiment with the single wire Bosch universal type (no heater ) which is only about $ 25.00 from one of the supermarket auto parts chains . It wokrs for me and my car passes a fairly stringent dyno emissions test with it .

Right. But with a proper 3 wire sensor you would be able to pass smog checks sooner, and after extended idling. Sure that may be meanignless to you, except all those cold starts where you're not being smog tested.. you're still polluting quit a bit.

- alex

'85 244 Turbo | ~145.5k miles

Get a UNIVERSAL 3-WIRE O2 sensor!!! It should cost $40-$60 at a local auto parts store. DO NOT use a single-wire sensor for your 1990 car!

Several people have adapted OLDER 240s to use the single-wire unit, but "newer" 240s have engine computers that are DESIGNED to use 3-WIRE SENSORS!

As you know, the 3-wire unit has a heating element that allows it to QUICKLY reach its operating temperature (600+ degrees???). If you install a single-wire O2 sensor on a "newer" 240 that uses a heating element, here is what happens: the engine computer checks the O2 sensor after several seconds; the single-wire sensor has not heated up in time, so the computer thinks it is faulty; an error code is set, and the "Check Engine" light appears. If you reset the error code and start the car, this will happen again and again.

This occurred to my 1991 brick several weeks ago. I thought I was saving money by installing an inexpensive single-wire unit, but I did not know how the heating element was tied in with the "Check Engine" light. I posted a message, and guys on the Brickboard immediately told me the cause. A few days later, I replaced it with a 3-wire sensor.

BOSCH Universal 3-Wire O2 Sensor - Part #13077 - $47.99 at AutoZone

[[ southern fried volvo - '91 240 123k mi ]]

Makes sense. Mine is 1985 model which had no trouble code features .

They work for me. The way I understand it, there is no difference in the sensor itself, just the custom made-up wiring harness for a specific group of cars makes the exact-fit sensor so much more expensive. Of course, it is easier to install the direct replacement sensor which may outweigh the price difference should you be paying for tech time.
--
Art Benstein near Baltimore