Odd drivibility problem

[Mediablitz]

I have an interesting problem with my '95 525iT.

The car since yesterday when it reaches a certain operating Temp. (15 minutes on the road from a cold start,) it will start missing as if the car is not running on all six cylinders.

The last time this happened, I listened to the exhaust note to make sure it was indeed missing and to check if there was any smoke coming out. (No)

I noticed a not-so-faint smell of Sulphur at the tail pipe. I checked all the plugs and they all look good and consistent between cylinders. However once the car has stopped for a while and cooled down, when it gets restarted the problem goes away and I can drive smoothly again. I put different gas in to see if that made any difference and now I wait. Could the O2 Sensor failing do this? Any ideas?

[Mediablitz]

I just read in Bentley's that the O2 Sensor doesn't start functioning until the temp reaches 600.F. To continue with my problem, I just drove the car around c 15 miles and no issues. The temp of the engine had not dropped down to cold yet ( it was on the 1/4 mark when I started the car.)

Since I got no replies, I'm going to expostulate and suspect that the O2 sensor is still at fault. It kicks in at 600.F and stays engaged or active for a time until the car is restarted when it is already in its "active state." (i.e. WARM) If the car is left to fully cool down, the Sensor has then actually de-activated and the trouble begins again. Read Stuck Sensor, slow to react.

Somebody tell me I'm full of sh#t before I spend $$ on the damn thing. BTW Is there a cross reference with Ford for this O2 Sensor? Has anybody tried a generic sensor and had good results?

[Karl]

If you can splice a wire, the generic sensor is fine (that's what I use) It's the same Bosch sensor, with about a foot of wire instead of the BMW connection. Pull your old sensor, cut the BMW wire off and splice it to the new sensor.

[Mediablitz]

Which generic sensor? Do you have a part #? Who makes it? I'm assuming Ford.

[Mediablitz]

Then again I may just order the real one from BMA. So damned inexpensive.

Notice I didn't say cheap.

[John 535is (Sydney)]

Get the right one first up. The problem with splicing in another one is that the cables are not your standard copper but a high temp type that are a pain to join. It looks pretty messy and then you have to tape them. Once the exhaust temp is on them for some time it not pretty, unless you can find some way to move the join away. And then, if it has not fixed your problem you have this nagging feeling that maybe your join wasn't perfect. Funny thing is, the prices don't vary much, but there are numerous different cables for the BMW. My mechanic ordered in 5 different ones, all listed as suitable for the 535, and in the end I went to the importer and went through the boxes till I found the correct one.

John 535is