Replacement of oxygen sensor
 

The time has finally come to replace these expensive little buggers in my E36 328is. I only need to replace the pre-cat sensors. Is it necessary to get the special tool for this?

If you can get to and loosen the sensors with other wrenches, such as box-end, then you probably will not need the special oxygen sensor socket. In any case, this socket is only around $10, so it's no big deal.

I already have the oxygen sensors but not wrench. I'd rather not wait a week to to get it shipped to me, so I was curious if anyone out there has done this without the special wrench. It would save me the trouble of jacking up my car and putting it on stands just to see if I absolutely need the wrench.

This "special wrench" you call is nothing more than am open-sided socket. You should be able to pick one up at a local auto part store. They cannot cost much more than $10, so there is no need ordering one on the web.

Thanks Yurick.

22 mm open end wrench wortks better htan the socket. especially if doing it flat on your back under the car.

15/16 also works if I recall.

buy generic "cut in" sensor...less than $50 at Amazon. research and make sure your get the right wire count (3 o0r 4)

do not use ebay as a source. the main guy there is a crook. sells a 4 wire to fit an 84 (*which is a 3 wire) and blames the customer for believing his ad.

Depending upon the year of the car, some are easier to get to than others. The one on my 318 was near impossible to remove without the tool The 325 was much easier...

-Wayne