100,000 mile check engine for 02 sensor?

[Jeff in MN]

Hi all,
Addiction continues as I just picked up our 4th bimmer this week. This one is a 98 740i with 100,180 miles. My question is about the check engine light. It just came on this morning for no apparent reason. Is it programmed to illuminate at 100,000 for replacement of the 02 sensors?

On a related note, the wife says the 87 535is needs to go. If you have any interest, let me know. I am in Minnesota, but the car came from NC in 2002, so the body is in great shape.

[shogun]

Do a stomp test to get a fault code or ask the dealer for a fault code readout. Stomp test described on my website below.
If the O2 sensors are really 100.180 miles in, then I would change them anyway. They get slow.
https://www.automedicsupply.com/faq.php?
But the check engine light is not programmed to give an alarm.
Even if you get a fault code O2 sensor, it might be a different part which has a problem such as the air mass meter. The O2 sensor just measures a wrong fuel/air mixture.

[Jeff in MN]

Went to Checker Auto and borrowed their code reader. It was P442 - Minor leak in the evap emissions control system. i.e. The Dang gas cap was loose.

FYI - I tried the stomp test yesterday to get codes, but got nothing. Think it has something to do with OBD II vs. OBD I.

Anyway, got the code cleared and we are off and running.