1990 Volvo 240 Oxygen Sensor

UpstateNY · Post by **UpstateNY** » 17 Feb 2009, 15:03

I have a 90Volvo 240, standard, B230F engine. The dreaded Check Engine light illuminated, which led me to run diagnostics, whereby I got a faulty oxygen sensor code. Pretty straightforward job I thought. Ho ho.
First, the dealer will sell me a sensor for $237, my auto parts store will sell me a Bosch (13034) for $191, and I see Bosch sensors on ebay for $75-$185. And, I see BeckArnley and Standard Motor Co for even less. Why the price differential for the Bosch sensors – do you know? And overall, from $21-$191 - what’s the difference? I could replace a lot of $21 sensors for that $237 dealer price (and from other Volvo experiences I would likely regret the installing $21 sensor). I also see reference to splicing wires, connectors, etc. What should I look for – or look out for? I prefer the Bosch, but why is it only $75 on ebay?
Secondly, I traced the sensor wire into a common “cable” and can’t tell exactly where it comes out in the engine compartment. On the firewall, I believe but how do I know which one it is? Continuity check? I have brake wrenches – are they OK for removal of the sensor? And once I get a new sensor, are there any secrets to installation? The only difficulties I can envision so far are not stripping the sensor I am removing, and having to thread the connector up to the engine compartment.
I appreciate any assistance. Especially with selecting a sensor. I hate spending money unnecessarily and wasting money on inferior products. Thanks.

Post by **billofdurham** » 17 Feb 2009, 15:37

The only comment I shall make about eBay is that some of the items are not exactly as advertised.

Check both of our sponsors using the links at the top of the forum and also check out this post: https://www.matthewsvolvosite.com/forums ... =4&t=18600

Splicing the wires is not a big problem because you cut the old wires near to the O2 sensor and splice in there. No feeding of wires through bulkheads etc.

For removal it is better to use the proper tool. Apparently this is available to rent or buy at Autozone.

Bill.

UpstateNY · Post by **UpstateNY** » 20 Feb 2009, 08:23

Thanks Bill. I appreciate your advice and agree with you about watching the ebay transactions. I'm sticking with a Bosch sensor. For one reason, I don't think wire connectors under the car are conductive to longevity. Do you know where the connector end is on the firewall?

Post by **billofdurham** » 21 Feb 2009, 11:37

Do you know where the connector end is on the firewall?

Unfortunately, I don't.

For one reason, I don't think wire connectors under the car are conductive to longevity.

Whenever I have to splice wires, whether or not they are exposed to the elements, I always solder them and cover them with heat shrink tubing. I was introduced to this method of splicing some 30 years ago by a 'technical wizard' who spliced wires for an underwater pump. It worked for years.

Bill.

UpstateNY · Post by **UpstateNY** » 23 Feb 2009, 09:40

Thanks Bill - the solder, shrink wrap method is also the one I use. I found the connector, it's in the engine compartment on the left side, threaded with a large cable bundle on the firewall. The sensor connectors are secured behind the shock tower with a plastic tie. They key is there are two connectors: a multi-wire and single wire. The single wire is connected to a green wire. I found that green wire clue in a Chilton book. Go figure - I guess on occasion they really do offer some rare insight. Anyway, I have a sensor on the way. I'll pass along any other insights or disasters.