I've been noticed that at highway speeds, when I fully let off the gas and coast my truck feels like it's engine braking. It used to do that when I had the exhaust wide open, but I never recall it doing it when I had full exhaust. And it coasts just fine at under 50 mph, it's just at highway speeds. It almost feels like someone puts the brakes on and then when I hit the pedal again it gives a tiny jolt. Thoughts?

 

i think that is called dynamic fuel cutoff or something like that. someone with a little more knowledge will probably chime in.

 

I checked the DFCO setting and they were identical to my old tune

 

Disable DFCO alltogether. That's what I did. ******* **** doesn't increase mpg's hardly any and jerks the drivetrain.

 

How do I disable it in EFI live?

 

Try setting B3313 DFCO Temp Enable to 140*C (284*F) or whatever Max is in your tune. The ECT will never get to this temp and that should disable DFCO. I did that in my tune and I still get DFCO when I decelerate hard? It does not seem to engine brake but the AFR goes to 20.0 on the WBO2.

 

Well, that's exactly what I did. I set the ECT enable to 250 F. Went out on the highway and now it's perfect, no more DFCO crap. Coasts nice and freely now.

 

I made my DFCO slightly more aggressive and I like it because I do use it as an engine brake and just coast instead of applying the actual brakes.

 

I hate the feeling of the truck slowing down as I let off the gas. Also, it gives a nasty jerk when you hit the pedal again.

 

hmm, ive seen where people say DFCO really helps MPG. Try to report back....