Need help with engine error codes

[mtitus]

My girlfriends 96 318ti with just over 100 K miles has had the check engine light on for about a month, so I had a friend plug it into his diagnostic system.
Here are the codes it gave us; P0301- CYL #1 MISS FIRE, P0302- CYL #2 MISS FIRE, P0303- CYL #3 MISS FIRE, P0304- CYL #4 MISS FIRE, P0170- FUEL TRIM MALFUNCTION BANK #1, P1174- FUEL TRIM ADAPTATION ADDITIVE BANK #1 MALFUNCTION. I am assuming that the cylinder missfires are a result of the fuel trim malfunctions considering the car runs relatively normal besides a rough idle and its not quite as peppy as it used to be. What I was wondering is what parts are needed, how expensive are the parts and how easy is the repair? Any info would be greatly appreciated.

Thanks
mtitus

[BMWCowboy]

Sounds like you need a crank case vent valve>>very easy to replace on that car >>held in by 2 screws>>upside down ~

[Wayne 962]

Frankly, I would reset the codes, and then see what trips. The computer saves the codes forever, so you will want to clear the system and see what trips first. That will be your starting point...

I.E. the mis-fire code (since it is on all cylinders) is probably symptomatic of another problem (possibly the O2 sensor?).

-Wayne

[sayah]

How does one turn off that enoying "Air Bag" flasher malfunction error code light without a trip to the stealer? Mine keeps flashing then remins on despite a perfectly operating system.

The corporate "legal" was working overtime on this one.

[mtitus]

Thanks for the info on the crank case vent valve. I replaced it the other day, and the car runs great. There is a significantly noticable difference in the car. I was amazed at the ease and cost of the fix after I consulted some shops and they gave me estimates in the thousands and suggested that I get rid of the car because of the cost of the fix compared to the value of the car. As for the second post I replaced the O2 sensor about two monthes ago hoping that was the issue. However that did not resolve it, but thanks for the reply. Like I said the car runs great now but the check engine light is still on. Assuming the car is fixed how long will the light stay on?

Thanks again for your help,
mtitus