Louie, a grad student asks:

>From: ljr7_at_po.cwru.edu
>Date: Tue, 05 Nov 1996 14:01:13 -0500
>Subject: O2 sensor for e30
>
>Hello all,
>
>I have a quick question about the O2 sensor in my car. The car is running
>kind of sluggish and I think that the O2 sensor is the cause. I got a quote
>on just the sensor, but using the old connector. This chops the total price
>in half for a new sensor/connector pair. Is this smart to do, or should the
>whole thing be replaced? The dealer quoted $135 for the sensor/connector
>pair, while the sensor by itself from another source is only $70. I thought
>that I had read somewhere that the connector is what usually goes bad, but I
>can't find that source or remember where it was on the net.
>
>
>Thank you in advance
>
>Louie Rendek
>graduate student
>Case Western Reserve Univ.
>Clev OH

Louie, somewhere there must be an O2 sensor faq - including the part# of the Ford (made by Bobby Bosch) sensor I found that worked just fine with my '87 535i (big-six-engine). Dunno if your E30 would use the same one. The one I found is a DV505, 3 wire, heated Bosch sensor.. cost around $45 from Ford (vs $135 from BMW). Worked fine.

As far as the connector going bad - rare if ever. The sensor itself wears out, it depletes itself in operation, it goes kaput, toes up, dead, non-functional. Usual interval is around 50-70,000 miles which is why BMW recommends replacement at minimal 50k intervals.

To install the Ford sensor (if you have a three-wire) requires some minimal electronic capabilities, as well as the talent of telling black from white (there are three wires - if I remember right, two whites - heater wires, and a black signal wire.. or the other way around. Doesn't matter, hook white to white and black to black and it will work).

If your E30 uses a 'one-wire' sensor - there are even less expensive alternatives which will require you trundling off to an auto parts store and finding a universal 1 wire Bosch replacement (cost around $25).. I'm assuming you have the three wire given the BMW price you quoted.

BTW - if the parts dude at Ford gives you a hard time about DV505 (it could be "DY505" - brain fade), tell'em you want one for a 1987 Ford Mustang V8.. dat's the one.