AFR adjustments
 

Hi,

I have a MY2009 with UpREV Tuner. The ECU is a 1EL5B.

My mods are: GEN3, BerkHFC, Nismo CatBack.

My question is:

Why twice a year I must readjust AFR Compensation?
(i.e. if target is 12.6 I read 13.2 or in the other season 11.5 )
- It's a problem of UpREV that does not compensate changes in environment? (i.e. hot season or atmospheric pressure)
- It's a problem of my setup (GEN3)?

Note that The MAF works correctly, in my logs I see always the full excursion range in Volts.

What do you think?

first things that come to mind is dirty particle getting stuck to the MAF sensor.

but the next obvious reason is your Intake temps calibration was not adjusted. it is a simple table that you have in the Fuel section section of Uprev. Unless its a Pro feature only which i do not know, the file below is the ROM i had for my 7AT as an example.

Then ofcourse there is a separate Fuel Compensation for Cold which is used if the Coolant is below 70-75C (158F-167F) then it will switch to the main table.

Yup ! You're right , it's just that map.

I must adjust twice at year the compensation map....

Seems that the MAF does not read very well...

Obviously, the MAF are mounted correctly.....

Could it be due to oxygen level in the air?

Let me explain, in the year period the air polution is at its highest wright after cold season, close to summer the nature starts to clean up the atmosphere.

If you MAF table is adjusted sooo good as to be very sensetive to the enviorment it might have an effect, its like altitude, less oxygen. Causing the problem.

PS. Thats a stock fuel table i never liked its too much fuel for me on idle and low rpm, i personally started there. Just my 2cents.