yevgenievich

iTrader: (1)

Have the following two codes that keep coming up.
0x7E8: P1174 - Fuel Trim Cylinder Imbalance - B1
0x7E8: P1175 - Fuel Trim Cylinder Imbalance - B2

Trying to find information on what exactly triggers them if anybody has some to share. 08 e38 truck ecu running bbc. Was starting to wonder if I really do have a vacuum leak somewhere, of if tune triggered.

yevgenievich

iTrader: (1)

If anyone have any advise, I am still consistently getting P1174 - Fuel Trim Cylinder Imbalance - B1. Except when towing a trailer, then it seems to stay off.

So far tried the following:
Two different intake gasket sets(currently on thicker intake gasket set)
Swapped o2 sensors side to side
Swapped injectors side to side
Adjusted valve lash(engine running method)
Capped off pcv system from the intake

Still coming up with B1 cylinder imbalance. Does anyone know what ecu checks to determine the code?

yevgenievich

iTrader: (1)

I think to have figured out what triggers it. Watching the logs and when it shows up, looks like there are some spots with very light load(some times on throttle release) higher rpm that current tune has lean spikes greater than usual dfco. That is when the code seem to come up. Adjusting timing on low spark mass mid rpm area down made one of the conditions go away, but later driving there was some other spot that made it come on. This also explains why it would not show up while towing, as loads were always greater.