Item is a new factory boxed oxygen sensor 11 78 1 286 638 / 11781286638 for use on the later '80's BMW FI systems. Used on the E21 320i up through '83, E30 325e and E28 and E34up through vintage year '91. If your car is running rough or will not pass smog, this may be the culprit. Factory retail for this item is $267! but offered here at great discount. UPS or post to add $8 at auction end to USA addresses and $35 overseas post.