Page 1 of 1
S300 Flex fuel
Posted: Tue Aug 04, 2026 7:03 am
by Knox
Hello, I have interesting issue. When I choose "digital s300 an0 (s300 v3 only), air fuel ratio goes to around 40 % richer. Is it normal? My flex sensor is gm 13577429, I used 2.2kohm resistor instead of 2.4kohm resistor because I couldn't find 2.4kohm. Does this make any issue like this ?
Re: S300 Flex fuel
Posted: Tue Aug 04, 2026 8:59 am
by Spunkster
Has it been tuned for the ethanol content being used?
Re: S300 Flex fuel
Posted: Tue Aug 04, 2026 1:41 pm
by Knox
not yet because when I notice this big change in afr I wanted to make research to understand why ecu adds too much fuel when I choose “the s300
Re: S300 Flex fuel
Posted: Tue Aug 04, 2026 2:08 pm
by Knox
Knox wrote: Tue Aug 04, 2026 1:41 pm
not yet because when I notice this big change in afr I wanted to make research to understand why ecu adds too much fuel when I choose “digital s300 an0”. Is ecu add fuel in background and if I remove the added fuel and tune from there. is it possible to afr change again ? or it just happen when enable the flex fuel? by the way ethanol content sometimes works sometimes don’t work. Is it because of different kohm resistor?
Re: S300 Flex fuel
Posted: Tue Aug 04, 2026 2:43 pm
by Spunkster
If you change the fueling it will change the AF.
This must be properly tuned.