I am reading a catalog from Atlantic British/MiniCarparts.net. One of the items is the Catalytic converter oxygen sensor. The description claims that the oxygen sensor should be replaced regularly.

Is this true? And if so, what would be considered regularly?

 

Did they happen to specify front or rear? or both?

Unless you had SES light that required it's premature replacement, and depending on your vehicle's state of tune(rich/lean), I would think that 60-75k would be a pretty good interval on the factory sensor.

 

They are saying front and rear. Here is the link to the web page:

http://www.minicarparts.net/Parts/M3095.cfm

 

I've seen 50K tossed about, but don't know how much of that is marketing by Bosch vs. vehicular requirements...

 

BMW says 100k on other models.

 

Most people don't even think about replacing the O2 sensor until it goes bad. Considering they live in a rather harsh enviroment, regular replacement does make sense.
I wouldn't recommend using anything other than a genuine BMW/MINI part.

 

unless your getting an SES light or noticing some drivablity problems it really isnt worth the cost of replacing the sensors. the ecu is able to adjust to the degradiation of the sensor and once the sensor is getting worse youll start to notice difference in engine operation and possible getting lean or rich codes before youll get an o2 operation code. it is also sometimes recommended that if you replace the upper sensor you should also replace the lower sensor at the same time. has something to due with the learning curve of the ecu. i wouldnt change the sensors unless it is necessary. the warrenty for the sensors is 100k i believe.

sorry for the mildly long post

 

Thanks for the info everyone. I will now return to my worry free motoring.

 

Has anyone cross-ref'd this part number from the OEM?? From the dealer it's about an arm plus half a leg. It should be a "normal" O2 sensor, correct?

 

MINI uses a 4 wire, heated sensor. More expensive than most. Cheapest I've seen it is $189. Each.

 

*gag*
My "check engine" light has intermittantly been on. I called the MINI service dude and he said the change of winter to summer fuel is messing up O2 sensors. Sometimes I have had rough idling. Is this something someone mechanically challenged (me) can change out?

 

If you've got a 22mm wrench and some patience, it shouldn't be a problem. I haven't done a MINI, but have on several other cars.

 

yep its not to difficult. just dont bust your knuckles when the sensor decides to break loose. also its a good idea to put some anti-sieze on the threads but make sure you dont get any on the probe thats in the exhaust flow. torque spec is 28 ft. lbs or as tight as you can get it.

 

Replaced my pre-cat sensor with a universal 4-wire. No problem with removing and replacing the sensor. It came with a nice splice in kit to attach to the original connector.

The details: Bosch 15729. O'Reilly had it listed for a 1997 AMC-JEEP grand Cherokee. The irony of that! My out-the-door price was $63.59.

 

Has anyone else tried what goaljnky did? I think I need to replace my o2 sensor but really dont want to pay that much. I would rather spend the money on cold air injection.

 

Rockauto.com

ACDELCO Part # 2132908 {#19107252}
SENSOR,HTD OXY(POSN 1) IN EXH MANIFOLD/CROSSOVER-4 WIRE
SENSOR,HTD OXY(POSN 3) POST CONVERTER-4 WIRE$96.790.00$96.79

 

149K miles on the original sensors. I'm waiting for the hammer to fall.

Jim

 

Unless that is a universal, I don't know where that PN came from as this is the one I've always seen:
http://www.partsamerica.com/productd...pe=291&PTSet=A
And FYI, $125-150 is average for the most part. Some get up into the $250+ range with an OE Honda wideband 5 wire the most I've ever seen at like 400 I think.

 

just put one from MINI in when it finally fails. that way you know it should be good for x amount of time. and the rest of your mods are still based on a factory reading to the dme from the o2.

 

More often than not, the O2 sensor works fine (with a little help from the ECU) then fails completely. If the SES light isn't on and you don't have a code for O2 sensor failure, don't worry too much about it. Replacement can be a minor PITA, but it's not an emergency when it does fail. Power is degraded somewhat, mileage goes in the toilet (wait, at these fuel prices, maybe that is an emergency). The car goes into "Limp-home mode", but is driveable.

 

Over time they slowly lose metering ability and that comes with power off a little and slightly less gas mileage but then they usually give up the ghost fairly quickly after that. Once they go, the car just runs massively rich. It's nothing bad, just kinda runs like crap and mileage drops off quick.

 

Like others have said, the DME (engine computer) will compensate for normal aging of the pre-cat sensor. once the sensor falls out of range, the SES light will be illuminiated and a code stored.

The post-cat sensor does nothing other than monitor the health of the cat itself. So, absolutely no benefit in replacing the post-cat (rear) sensor unless it fails. The post-cat sensor is sort of like a qaulity control device. last check before things go out...

 

^^^Yep, before cat monitors A/F ratio and determines mixture, after cat measures cat efficiency.

 

http://www.amazon.com/Bosch-15738-Ox.../dp/B000BZL08U

Both sensors for $123 and change

 

Are we sure about the #'s. We have two different #'s for the Bosch. The o's are the same.