P2096 and P2098 codes thrown

[razorboy]

Originally Posted by X53Jay4.8is

Well thats a good start to rule out a possibility.

Now that I think about it, there isn't any reason I couldn't smoke from the tailpipe towards the engine. Same net result.

[razorboy]

Quick update

Was listening around to the exhaust today under the engine and can't tell for sure but maybe there is a leak of some sort?

What I did certainly identify that the rear bank is running much hotter than the front one. Used my infrared themometer and when compared, the temp on the front manifold was around 240F while the rear manifold was at 500F. Guess there really is a lean condition going on.

Is there anything now besides a plugging up cat that would allow that much temperature to be created?

[kevinkay]

dont confuse cause and effect - in theory running lean does burn hotter.

[razorboy]

Originally Posted by kevinkay

dont confuse cause and effect - in theory running lean does burn hotter.

Well I certainly have the effect - lol.

Smog test is coming up too so I got to get on it now.
My mind keeps going to what could be problematic on bank 2 that doesn't affect bank 1?

Since the truck seems to run pretty good and I have no other codes outside of lean ones, I have to assume its post engine. Either issues with the O2 sensors (new and no codes) or else the cat is giving up the ghost.

[razorboy]

I like it when I am able to come back and show a result on a problem. Hopefully this helps someone down the road as it was pretty much driving me mental.

I had lean codes for quite a while but was pretty slow in getting around to fixing them. Registration / smog time is a great motivator to get things fixed but last year, believe it or not, my CEL turned off for about two days and I was able to slip reg in without fixing it lol.

I decided to attack some of the issues finally and I have replaced a lot of parts on my X5 anyway. The CCV system, DISA valve, VANOS rebuild and a host of other items were all replaced just as a path to a better running truck. Despite all of this, I simply could not find the answer to the lean codes and have even smoked the vehicle looking for air leaks but none were found. I doubt there is much anyone could suggest that I didn't already tackle.

So last week I decided to replace the fuel filter as it was unknown how old it was. I bought one online and when it arrived I discovered that mine needed the filter with the integrated FPR. Bummer but I had to order the proper one in and wait a little longer. I will tell you that rear cover is a huge pain in the ass to remove made worse by a stripped thread on one of the cover nuts to body. It would simply spin in place and after what must have been 90 minutes of wrestling with it, I finally used every conceivable tool I had access to and broke the entire stud off. There was simply no other way and well, one less nut to remove next time.

So on the fuel filter there are three fuel hoses and a vacuum line for the FPR. Normally, the regulator is situated in the engine bay closer to the fuel rail but god bless BMW for hiding it away under a cover with about 100 fasteners lol. The first thing I pulled off was the vacuum line which is connected from a hard line to the FPR via a short piece of rubber hose (maybe 3"). As I grabbed it, it crumbled in my hand! It was like dust formed in the shaped of a hose.........Right away I got excited because I realized that when we smoked the vehicle, no one even thought to go and look to the back and see if there was anything coming out of the area and since I had no idea there was a FPR sitting back there, I wouldn't have even imagined it. Quick cut of a nice new piece of silicon hose to reconnect the line to the FPR and after the filter was installed, put the bag-load of fasteners back in place and gave it a go. Reset the CEL and set up my reader to monitor live data.

Initially, I was seeing about +1.5 - +3.7 on the LTF adjustments and I didn't know what the limits were for the computer to decide on throwing a CEL so I just kept driving and kept monitoring. It did go higher over varying driving conditions but never went over +8 % fuel added and I have not seen a code for lean thrown since. I do have a code P1447 for the DTML pump but I had replaced that already with a known good unit and I still get that code when I fill the fuel tank. It is probably a contributor to the lean codes but now I think it is the last contributor and I just have to resolve this one additional issue.

Suffice to say that if you are getting lean codes like a P2096, that little piece of hose could indeed be your problem as well and although it is a pain to get to, it makes sense to replace your fuel filter anyway and while you are right there, put a new connecting piece of silicon vacuum line on there between the hard line and the FPR on the fuel filter.

Good Luck!

[Crowz]

This should save someone some nightmares for sure!

Thanks for updating when you found the fix.

[Fifty150hs]

Originally Posted by Crowz

This should save someone some nightmares for sure!

Thanks for updating when you found the fix.

[razorboy]

Originally Posted by Crowz

This should save someone some nightmares for sure!

Thanks for updating when you found the fix.

You're welcome.

It always drives me nuts when threads don't ever get closed with a resolution. It has taken me quite a while to find this little demon myself but since the truck was running well anyway, I didn't worry too much about it. Now that I have tracked down the culprit, maybe someone can find the issue on their vehicle quickly and avoid all the head scratching.

[kevinkay]

YES, thanks for posting results.
Just as a general FYI, the other end of that hard vac. line turns back to rubber on the other end and attaches to the rubber intake boot (that SO often gets ripped).

photo is my 3.0