2001 330i with a 0 LTFT on bank 1, -3.9 on bank 2. Also giving the codes P0140, P0141 and P1155. At a bit of a loss, no idle fluctuation, no DISA rattle, fuel efficiency is completely normal.
I did. 3 of the stock studs had been replaced at some point and the last remaining stud snapped during removal (exhaust dropped for a guibo/csb replacement). I ended up drilling out the remainder of the stud and replacing all of the bolts with stainless.I see you have done your Exhaust gaskets, Did you change bolts in the cats at the same time.
I can do another cold start log tomorrow, how long should I let it run?Yes, the cold start log did not run long enough to let the DME get into closed loop. So, we can't see the full pre-cat O2 sensor heating cycle. But the pre-cat O2 sensors were working OK in the drive log.
Until you get to 1/2 operating temp of around 45C (100F). That is the needle on the temp gauge at just over the 1/4 mark. Being winter where you are, that may take a while.I can do another cold start log tomorrow, how long should I let it run?
I didn't, the main reason for dropping the exhaust was access to the driveshaft (CSB was completely torn apart) and for transmission mounts. I'll have to take a look at the connections on the valve cover tomorrow (got an ice storm where I live last night).When you did the Exhaust gaskets, did you replace the post cat o2 sensors? Best time to do this. The post cat sensors can be tough to get out without taking down the manifold, I tried many things.
Double check your post cat connections at the valve cover? Could be incompletely inserted! I did this. Look at the 50 kid utube video on taking manifolds down, It involves removing motor mount and jacking engine to lower front cat.
Is there any way that I could check/test the sensor?There are not many parts that cause bank specific Lean trims. One is a failing pre-Cat sensor.
I do not, nor are there anti-fouler's installed, although that is something I will do if the cats are clogged.Do you have cat-less headers? Have the post cat O2 sensors been fitted to anti-fouler's or similar extensions to move them out of the normal exhaust flow path?
The easy way is to unplug them, start the engine and see what codes pop up.Is there any way that I could check/test the sensor?
Blocked cats cause rich fuel trims under load. We are not seeing that in your fuel trims.Would it be cats even if the fuel trims are still lean?