Dear Friends,
Months ago, I had de P0174 System Too Lean Bank 2.
My car had the following symptoms:
- When starting the car from being cold, AFR goes quite lean (> 18) only after a few seconds of being Idle - After giving little gas, AFR suddenly goes lean (15 - 17)
- Sometimes with gentle acceleration, AFR progressively increases one unit by second from 14 to 18. When it reaches 18 in one second ECU enriched mixture and drops to 14.
- When the above symptoms occurs in my OBD2 scanner, FuelTrim for Bank 1 is 1-1.5% and FuelTrim for Bank 2 is -25% (ECU leans the mix), both ends!
- After driving few miles FuelTrim is more stable but leans at low accelerating.
There is no other code but only the P0174. I have Magnaflow Cat Back Exhaust, CAI INJEN, OBX Long Tube Headers (Cat was removed), AEM FIC and AEM Fail Safe Wideband.
In my scanner Front Sensors (Bank 1 Sensor 1 And Bank 2 Sensor 1) Oscillates between 0 to 9 volts as expected.
Possible solutions I tested:
- Front O2 sensors are connected directly to ECU and is not intercepted by AEM FIC.
- I Disabled Rear O2 Sensors with Hackish reflash.
- I swap front O2 sensors.
- I clean Injectors.
When I Swap the front O2 sensors, I expect to get P0171 Code (System too lean Bank 1) when there is a problem with the bank 2 O2 sensor - but the P0174 Code appears again!!!
Why does ECU lean mix (FuelTrim -25%) only for Bank 2?
Is it not injectors or fuel filter because Bank 1 is not lean only Bank 2, neither a leak because ECU FuelTrim is -25% for Bank 2.
If you had any ideas or suggestions you can share, I would greatly appreciate it:
Thanks in advance.
Months ago, I had de P0174 System Too Lean Bank 2.
My car had the following symptoms:
- When starting the car from being cold, AFR goes quite lean (> 18) only after a few seconds of being Idle - After giving little gas, AFR suddenly goes lean (15 - 17)
- Sometimes with gentle acceleration, AFR progressively increases one unit by second from 14 to 18. When it reaches 18 in one second ECU enriched mixture and drops to 14.
- When the above symptoms occurs in my OBD2 scanner, FuelTrim for Bank 1 is 1-1.5% and FuelTrim for Bank 2 is -25% (ECU leans the mix), both ends!
- After driving few miles FuelTrim is more stable but leans at low accelerating.
There is no other code but only the P0174. I have Magnaflow Cat Back Exhaust, CAI INJEN, OBX Long Tube Headers (Cat was removed), AEM FIC and AEM Fail Safe Wideband.
In my scanner Front Sensors (Bank 1 Sensor 1 And Bank 2 Sensor 1) Oscillates between 0 to 9 volts as expected.
Possible solutions I tested:
- Front O2 sensors are connected directly to ECU and is not intercepted by AEM FIC.
- I Disabled Rear O2 Sensors with Hackish reflash.
- I swap front O2 sensors.
- I clean Injectors.
When I Swap the front O2 sensors, I expect to get P0171 Code (System too lean Bank 1) when there is a problem with the bank 2 O2 sensor - but the P0174 Code appears again!!!
Why does ECU lean mix (FuelTrim -25%) only for Bank 2?
Is it not injectors or fuel filter because Bank 1 is not lean only Bank 2, neither a leak because ECU FuelTrim is -25% for Bank 2.
If you had any ideas or suggestions you can share, I would greatly appreciate it:
Thanks in advance.