P2272 (emissions?) issue - any help appreciated, inspection due!

[nikolai]

Hi all - 2005 3.0i, 232,000 miles here. There is literally not one instance of a P2272 code on this forum, so hopefully a resolution to this can also help someone else out in the future!

I have been chasing down what I believe to be an emissions issue that started to manifest itself about a month ago (of course, right when inspection is due this month ), mostly focused around O2 bank 2 sensor 2 (B2S2). Here is the story (sorry for length, but hopefully the details may help someone help me or possibly help anyone else!)

Beginning - Chasing P1093
P1093 code (pre cat fuel trim too rich, bank 2) shows up about a month ago not long after I installed a new CCV system, spark plugs, coils, and valve cover gasket. Thinking it was something wrong I did with any of those items, I checked and double-checked my connections, rubber intake boot elbows, etc, but P1093 would persist. I went ahead and swapped in the following new items: air intake distribution bar (with new o-rings), Idle control valve, pre-cat O2 sensors - no luck, P1093 still there.

Since I was also getting an intermittent P0411 (Secondary air injection system incorrect) and my (original) Secondary Air Pump was rather loud upon cold starts, I swapped in a new SAP as well. I haven't seen the P0411 again, but the P1093 was still there.

Discovery - Exhaust Leak
Not long after all this, another code pops up!: P0430 (Bank 2 Catalyst inefficiency) My next step was to try and swap the rear O2 sensors (prior to any of this work all O2 sensors were original) - however, upon inspection, I discovered that the 4 bolts/studs from the catalytic converter to the down pipe (2 on each side) were completely rusted out, causing both the 3-holed bracket to rattle and, worse yet, not holding the Bank 2 gasket completely tight, causing an exhaust leak!

So after paying a shop a few hours' labor to R&R bolts/gaskets, things are (I believe) buttoned up on the exhaust and - no more P0430 or P1093! At this point I still have the original post-cat O2 sensors.

The latest, P2272...
No codes for about 70 miles and then BAM! P2272 (Oxygen Sensor Signal Stuck Lean Bank 2 Sensor 2) shows up Thinking that the original O2 B2S2 got banged up/damaged when R&R'ing the exhaust bolts, I replaced it with a new one (Bosch). Soon after that, P2272 reappeared along with P0430(!). Having come across the non-fouler modification for fixing P0430, I went ahead and added it on B2S2. After driving about 60 miles I no longer have the P0430, but the P2272 just showed up again

Current state:
- P2272 code
- New pre-cat O2 sensors
- New bank 2 post-cat O2 sensor with non-fouler mod
- Original bank 1 post-cat O2 sensor

Any help/advice would be greatly appreciated. I am on the verge of taking it to a shop - this thing runs great (aside from this issue), but I need to get things resolved to pass NY inspection this month
I am also really hoping by cats are not toast!

PS: I do not have a BMW diagnositics tool, so I was running under the assumption that P2272 is related to B2S2. However, I found an alternate BMW definition for this code here: P2272 BMW Auto Trouble Code With All Car Models | Auto Trouble Codes - AutoTroubleCode.com I have not pursued this avenue of investigation yet, but perhaps I should?

Update: I just had my indy scan it with his scanner that can pull BMW codes - he doesn't see P2272, however he sees a few 3-digit emissions-related bank 2 codes for cat inefficiency and one for lack of a signal from B2S2(?!). I should have recorded the exact numbers he saw before we cleared them Currently at the stage of needing to drive to reset sensor readiness to see if we can reproduce the codes...

Lessons Learned
At least one lesson so far: P1093 can be caused by an exhaust leak