lean bank 1

[s57_s2k]

Hi

What can cause lean fuel condition by 24% in bank 1 ( driver side ) compared to bank 2 ? the car is f body with 416 engine , ls3 injectors , SD open loop tune. The fuel injectors and rail were checked and replaced but the condition did not change. All cylinders are firing ( checked with IR heat gun ) and LTFT STFT are 0% .

2000_camaro_rtt_1.hpt


thank you

[5FDP]

Are you using a dual wideband setup to watch this because the trims and everything are disabled?

If that is the case did you move wideband sensors side to side to see if it follows the sensor?

[mbray01]

sounds like you have an exhaust leak to me. with trims disabled, and using a wideband(i am assuming) if it reads different bank to bank, its likely an exhaust leak. I had a pin hole at the o2 bung that had me going crazy. was seeing huge fueling differences, for hole the size of a pencil tip. How big a hole is, and how far from the o2 will determine how much it affects the sensor

[s57_s2k]

Are you using a dual wideband setup to watch this because the trims and everything are disabled?

If that is the case did you move wideband sensors side to side to see if it follows the sensor?

yes , I am using two widebands, one for each side.

[s57_s2k]

sounds like you have an exhaust leak to me. with trims disabled, and using a wideband(i am assuming) if it reads different bank to bank, its likely an exhaust leak. I had a pin hole at the o2 bung that had me going crazy. was seeing huge fueling differences, for hole the size of a pencil tip. How big a hole is, and how far from the o2 will determine how much it affects the sensor

but it feels like real lean,not a measurement error . because when STFT is turned on and compensate for that lean, the engine idle much better. could this be ECU hardware fault ? or ls1 to ls3 injector adapter fault ?