LS BRAVADA

iTrader: (4)

Do the 04 cars use these. If not can they be turned on by a tune

Famous556

iTrader: (1)

I'm probably the last one who should be offering any info on tuning questions. But I could have sworn I read a thread on here or cf that said that the cts-v did not use fuel cutoff on decel.

MN_V

iTrader: (5)

The V does use DFCO, and it can be adjusted by the tuner. You can tell in the exhaust note and your instant mpg meter when it is active.

Your gen3 engine can be tuned for lean cruise as well.

punishmentcycle

iTrader: (6)

Leave it alone.

Blown_Red_97z

iTrader: (3)

I had this on in my gto. I would just leave it alone, your check engine light will always be on. So if you have to worry about smog, you won't pass with it on

DMM

DFCO is enabled in factory tune and should be modified when the cam etc is replaced to retain its function since it is based on MAP value. DFCO provides reduced emissions and increased MPG at no expense so I'll never understand why people do not tune this for increased functionality.

The lean cruise is in your tune, but turned off since the enable is set to 256 MPH. You'd have to populate the tables since they're set to zero and add lean cruise timing. I've done it, no big deal and it works. I got 3 MPG by updating DFCO to work correctly.

The guy that had a CEL had other stuff going on. Lean cruise does not set codes any more than the open loop fuel adder tables will.

MN_V

iTrader: (5)

Did you mean to say you got 3mpg by adjusting lean cruise for highway cruising? Or did you really get 3mpg by messing with DFCO? In stock trim mine already goes DFCO in 3rd gear and up anytime I'm in gear above 1500rpm and the fuel cuts back in at 1100-1200rpm (2nd gear you have to be in higher rpms so it's very rare to be coasting down from). I'm just curious how you improved upon it.

DMM

DFCO only. I don't have my laptop here with me, so I'm going on memory. I set it to defuel until 1200 RPM or 30 MPH IIRC. It was a PITA after switching to the 2 BAR OS since I lost resolution in the MAP, but it just took a while of screwing with it. The only way I can tell DFCO is active is if I have the wideband installed or I am logging and see the O2 sensors drop off. I know I got 3 MPG in combined driving with just DFCO as I went from 15-16 MPG to 18-19 MPG combined driving. Have no idea what the lean cruise could have gotten, did not have time to optimize the tune, but it did work (without triggering the CEL BTW).

crash41301

iTrader: (1)

Could some one elaborate on this lean cruise thing? Ive got hpt, i know how to tune, but i didnt think lean cruise workd on any usdm cars except the imported gto because the code in the ecu (that hpt doesnt provide access to) wasnt enabled regaurdless of if we turn it on and provide values in the tune. Are you all saying this isnt the case for the 04 v? Id love to enable it and get a few more mpg on the highway....

DMM

The option is there, last sub-tab under the fuel tab IIRC. Have to enable it by speed and set the parameters.

LS BRAVADA

iTrader: (4)

Thank you for the information