[nick]

since installation, ive been trying to do 3rd gear and up WOT to finish the custom mapping with Trebila, but car keeps suffer lean afr and high fuel trims
my mods are Meth(2 bm10 nozzles), BL coils, stage 2 turbos, vrsf **, oil catch can, sillicone inlet, aluminum outlet, jb4 mhd custom map, E50, stage 2 Lpfp

first code i got was 2C7C 2C7B 2C2D, and after dropping to E30 and map 1(15psi max) with meth could barely handle the fuel demands, we thought something was wrong and I replaced all 4 o2 sensors & hpfp,
now im still getting 2C7C code after replacing the all 4 of sensors.
logging after replacing all o2 sensors and Hpfp, 3rd gear WOT,
bank 1 afr is around 15 and trims 50+, while bank 2 afr& trims better (12.5 & below 50)

what else should i look into? ******** leaks? factory faulty o2 sensors? what are all possible things that could cause this? so i can check one by one until fix this issue.
thanks in advance!

[Boland01]

I'm sure you already verified this but have you tried switching the O2 sensor connections on top of the manifold? They are very easy to mix up especially if you put on new o2 sensors.

[nick]

already have.. grey in back black in front, only strange thing was that i bought bosch aftermarket o2 sensors and they dont have grey / black differences on top of manifold.

[Boland01]

There are two different oem O2 lengths. Most people do what you did (me too) is just buy two each of the longer length sensors and save the difference in cost. The only downside it's then easier is cross the connections at the manifold. Good news is if that happens you just flip the manifold connects.

Hope you find the root cause on what's going on here.

[nick]

if i crossed connections at the manifold wouldnt the both banks have issues? but i will still check and make sure again.

[Terry @ BMS]

You'd need to resolve any O2 sensor faults before starting to tune it.

[nick]

right, but im stuck after replacing all the o2 sensors... im sure they are installed right.
from the log, it shows that only bank 1 is suffering from lean AFR. could this from v band or ** gasket leaks?? i do have straight ***** so each banks have their own exhaust pipe line.
other than that, all the possible thing that can go wrong i think is DME connection to O2 sensors is fried? any ideas where i should check?

[nick]

logs updated, with meth i think they are better??
but without meth, map 1 will kick me out to map 4 ..
2C7C - Lambda probe behind catalytic converter 2, Signal

stage 2 turbos and lpfp, sillicon inlets & outlet, meth kit, chargepipe with tial bov, E30, downp ininstalled.


please help! ive waited so long for this turbo upgrade

map1 no meth : map1 meth trig 0 run1 - Google Sheets
map1 no meth : map 1 no meth 345th - Google Sheets
map1 yes meth : map1 meth trig1 345th run2 - Google Sheets

[Dave @ BMS/Fuel-It!]

Can you please upload the CSV?

[nick]

heres the csv file.

after this ive been commuting work (only light throttles) and sometimes my afr would be around 15-19 on light throttle.. kinda scary


this is on E30, stage 2 lpfp, stage 2 turbo, BL coil, 2*BM10 nozzles 100% meth, sillicone inlet, aluminum outlet, oil catch can.

this all happened right after turbo installation.