Whats going on? Suddenly abnormal lambda in WOT between >0.76?!-0.78 - normal is: 0.79-0.81

[typer86]

Hi Hondata,

I don't know why but suddenly in WOT the lambda value is between >0.76?! - 0.78.
I tuned the car value (map based) to lambda 0.79 - 0.81!


So the big questions is why suddenly the car runs rich?
Did you have any idea what is going on? I can not understand what is happen - I hope you can support me to identify the issue.
Thanks in advance.

What I checked:
#1 Reset ecu to stock - upload calibration again = same result
#2 Deactivate second lambda = same result
#3 checking lambda connection of the denso air fuel sensor = maybe OK (looks fine)
#4 Checking K&N filter = cleaned up - perfect conditions = OK

Planed checks:
#1 Change aif fuel sensor to OEM
#2 Checking spark plugs and change to new one if necessary
#3 change the OEM fuel pump to dw300c

Car modification:
> FN2
- Intercooled Rotrex supercharger C30-94
- RC750cc injectors
- Stock Honda fuel pump <= maybe dying?
- Denso Wideband primary O2 sensor <= miss reading? I will change upcoming monday to the OEM
- Stock catalyst converter <= full? But why no check engine comes up? second lambda is still active
- Invidia cat back sport exhaust
- Scoop in - K&N filter (checked and is cleaned up)
- Spark plugs NGK BKR8EIX <= maybe fouled spark plugs?
- Hondata 4 Bar MAP sensor


Here the calibration and the logs

MAFMAP.1.10.fpcal

Jerome-MAFMAP-2.10-2.fpdl

MAFMAP.1.14.fpcal

Jerome-MAFMAP-2.14-2.fpdl

Jerome-MAFMAP-2.14-1.fpdl

[typer86]

Log1 attached

Jerome-MAFMAP-2.10-1.fpdl

[Spunkster]

It seems like you may need to do some additional tuning on the VE tables. If you change the fuel pump you will need to do more re-tuning.

[typer86]

It seems like you may need to do some additional tuning on the VE tables. If you change the fuel pump you will need to do more re-tuning.

Thanks so much @Spunkster for your reply.
I will check the spark plugs first - so I can see if the mixture is to rich or lean...

'''
What I can say
> No noise from the catalytic converter
> No fuel smell
> Fuel tank was nearly empty (1/4 or so) - fuel pump was under stress
**

That is OK for me to tune /re-tune the VE tables - if the new fuel pump is mounted.
But I can not understand why suddenly the car runns still rich?! Because I am using the same VE tables.
Strange....

Which test you recommend to check if the primary O2 sensor is working OK. My feeling says the sensor is going crazy or the catalytic converter is in trouble.... But I am not 100% sure - so the sensor will be changed as next (upcoming Monday).

> What can you tell me about this: - Did you have another experience with this issue?
--> Maybe the fuel pump / fuel regulator / blocking catalytic converter
--> Can also the injectors create this issue?

Thanks for the technical answer