This is my first post. I recently bought a

2001 x5
75000 miles.
4.4 v-8.

Right after I bought it the ses light came on, I pulled the codes and it showed p0174 and p0171. (system too lean-bank 1 and 2)

I pulled the cover and noticed 2 hoses that looked like mush. They are located on the passenger side near the firewall and go to the drivers side near the firewall. I think they are connected to the oil seperator that everyone is talking about. I replaced those and the codes went away for awhile.

It came on the other day, so I pulled the codes again. It came up with p1158 and p1160. Fuel Trim Adaptation Additive Low (Bank 1) and (Bank 2).

I started with the cheapest things first. I got a new air filter cleaned the MAF and changed the Sparkplugs. ( When I pulled the covers off to get to the plugs, there was oil on the sparkplugs closest to the firewall on both sides). I reset the light and it comes on about 40-60 miles after i reset it.

FYI: The previous owner says she did not use premium fuel. I can't feel any problems with the car and it sounds normal. I am also averaging 17 mpg. It is cold outside. We have had a high temp of about 32 deg F for a couple of months. Any suggestions would help. Should I take it to the dealer or will they just tell me what the codes mean?

after the 40-60 miles are the plugs full of oil again? if not i would be looking @ 02 sensors...crappy fuel, fouled plugs and oil blow by makes for bad 02 sensors. maybe look for a cheaper VW raplacement, you might have to cut the cables to make them fit but could save huge coin too.

I will have to check for to see if there is oil. I've been putting premium cheveron gas in and have also added lucas fuel cleaner. It didn't seem to make a difference. Is there away to test to see if it is the 02 sensors or the MAF. Can the dealer or someone tell which one it is, or do i have to buy one and cross my fingers that i guessed right? Thanks for the info.

If you don't have any luck with the other options I would have a shope smoke test the intake to see if there are leaks on the intake manifold gaskets etc as I would imagine any intake leaks could assist with a lean condition.

There wasn't anymore oil. I noticed that the hoses were conneted to the oil seperator that everyone seems to have trouble with. These hoses were completely torn apart for who knows how long. Could this have caused damage to it? Is there a test that I can do to see if is not working? I am probably going to take it to the dealer tommorow, so if you guys have any other suggestions before I go I would like to hear it. If not, i will let you know what they say.

You need to reset the fuel trim adaptations after repairing an air leak. Only a dealer or someone with a GT1/DIS can do that.

Thank you Mad Dragon. Would resetting the fuel trim adaptations fix my problem codes?

Update:

I was on my way to the dealer and the light turned off. I have driven 80 miles since and it has not returned. (keeping my fingers crossed). Below is a list of what happened.

p0174-p0171 appeared
replaced oil seperator hoses
reset ses light
ses returned with p1158-p1160
replaced spark plugs, cleaned oil out of spark plug compartment, air filer and added lucas fuel treatment
reset light
light returned
light turned off by itself after 40 miles.

I knew it was to good to be true!! The Check Engine Light came on again. I pulled the codes and it is still p1158 and p1160. It came on while I was driving to work. It also lunged forward while I was stuck in traffic.Should I just replace the MAF sensor? Any other thoughts?

I have heard that BMW supplied Land Rover with 4.4L v-8's and that the MAF sensor is the same for both. I called the dealership and they wanted $360.00. Land Rover wanted $139.00. I checked the part numbers and they all checked out. Below is a list of the part numbers.

BMW 0280 217 814
Land Rover MHK 000 230

fuel trim adaptations do not need to be reset.

once the air leak is fixed, the DME will relearn the proper air/fuel mix needed, and adjust the adaptations accordingly.

Thanks, I am still waiting for the part to come in. I will post the results when get it installed. Has anyone had the same thing happen to them? What was wrong?

The part worked perfectly. It was exactly the same and everything is running normal.

fuel trim adaptations do not need to be reset.

once the air leak is fixed, the DME will relearn the proper air/fuel mix needed, and adjust the adaptations accordingly.If you reset the adaptations, the learning process takes much less time. You're already in the GT1 to clear faults, it wouldn't kill you to take an extra minute to reset the adaptations. It's part of the test plan.

I've had cars without faults set the MIL immediately after replacing intake boots, because the adaptations were not reset.

If you reset the adaptations, the learning process takes much less time. You're already in the GT1 to clear faults, it wouldn't kill you to take an extra minute to reset the adaptations. It's part of the test plan.

I've had cars without faults set the MIL immediately after replacing intake boots, because the adaptations were not reset.

True, but these guys that are getting their codes read/reset at Autozone or at their house with a generic scan tool won't be able to reset the adaptations.

Hmm, i usually run the quick delete after diagnosing my problem, then fix the car. Never had them come back on that quick.