So when I first got this car it had long term fuel trims of 3% so I assumed it is normal because the PO didn't toutch any of the lines , so when I went to change both cabin air filters that require you to take out the microfilter assembly I finished the job put them back on and now the ltft for both banks are about 11% I double checked if they were in good and they are, could a vaccum leak come from that location? Haven't toutched the intake boot or any of those lines yet. Wanting to take care of the leak so I can save my catalytic converters.
Not from the microfilter area itself. I would look for any vacuum lines that may be near by that may have or could have gotten disturbed.
Become a BMW CCA member! Click HERE to join and feel free to use my BMW CCA member #191509 as a referral.
2015 650ix GC (Moonstone/Cohiba Brown) <<~>> 2014 X5 50i (Space Gray/Mocha)
Not sure (without googlin' the pixozrz) where it sits on an M52TU car, but, the brake booster "sucking jet pump" device is notorious for sneaky cracking and leaking while still looking like it is whole to the casual eyeball. Inspect that guy - at least on the V8 that's pretty much in a spot where you'd whack it if you took out the cabin air elbow ducts (which shouldn't have been necessary to just do the filter, but I take my trays out when I do the filtters anyway to wash them down and check the bins below for debris etc. )
- - - Updated - - -
Oh and BTW, don't sweat the cats/O2's too much. I mean the idea to fix and corral trims back is 100% correct, but as long as you're not getting codes and lights, then it means the DME is currently able to trim out the fuel to a good point, therefore the O2's and cats are not actually seeing too lean/rich conditions because the trims are 'working'.
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
Bookmarks