AFR values

[bobjob]

I have been plugging in my mtune device more often now and i notice that i sometimes see my AFR at 15 or so even at idle for a bit. sometimes when im giving and holding partial throttle (highway speeds). is that normal? usually its arounf 14.7 or there abouts and less if pushing hard on the throttle. I worried i may be knocking or running too lean. the mtune device doesnt show knock like a regular cobb ap

I have the mp215 kit, FMIC, and catback.

 

[koozy]

normal.

 

[bobjob]

thanks!

 

[draxxus131]

Adaptive ecu, when at idle a car may try to achieve 20.0:1 afr ratio. For example, farm tractors achieve 60:1 afr ratio for fuel reasons.

 

[dyn085]

Adaptive ecu, when at idle a car may try to achieve 20.0:1 afr ratio. For example, farm tractors achieve 60:1 afr ratio for fuel reasons.

No, that's not right at all. Any FiST attempting to hit 20:1 at idle needs to speak to their tuner or be taken to the shop to be fixed.

 

[draxxus131]

Do elaborate. This is just my experience within the mustang realm amongst tuners.