MN_V

iTrader: (5)

Vehicle is a 06 LS2 CTS-V.

Mods are headers, high flows, standard 2.5" size magnaflow exhaust.

PCM is mail order tune from Jesse Bubb / Wait4Me.

Had it dynoed last year it was a little lean above 4500rpm around 13.2 so he asked I send it back in to him, which I did. Car runs fine but started datalogging and LTFT's on both banks are averaging about +9.5-11 over multiple 30 minute drives. I don't know if he did something to tune it that way to dump a bit more fuel when in open loop/WOT. STFT typically stay within +/- 5.

Should I be concerned or look into a retune? Thought I would ask around in addition to talking to Jesse later. Car makes good power according to my 1/4 trap speed. MPG is as-expected I would say. Car smells a little rich at idle but not obnoxious.

Thanks for any advice. I am not a tuner and don't know much about it other than the basics of how STFT and LTFT work.

danieloneil01

Do you log the car and send him the file for him to make adjustments?

MN_V

iTrader: (5)

That's what I'm looking to do. Just got the logger. Are .lgf files a standard format that can be sent to any tuning software?

danieloneil01

Doubt it. I would strongly suggest taking it to someone local to dyno and street tune it or buy bptuners and do it yourself.

Iam Broke

You can use either DashCommand or ScanXL from a google search. I suggest you find a local or email tuner that uses HPTuners.

LTFT's should be able to be dialed in to +/- 2 pretty easily with a little logging and tweaking.

Russ K

iTrader: (1)

I always disable the LTFT's on the Gen IV pcms. As either negative or positive LTFT's will be added to the WOT fueling.

Russ Kemp

redtan

iTrader: (5)

Negatives won't, but positives will.

That's why most people shoot for negative long term trims.

OP that's enough of a swing to warrant a re-tune. Generally trims under 5 are accepted, especially with a stock cammed car. Over 10 is just a tune that needs finishing.

MN_V

iTrader: (5)

Thanks for the comments. Jesse and I conversed. Before I do any re-tuning I'm going to change the plugs and maybe try a buddy's MAF to see if any of that is causing the issue. Car has 108k on it.

At >~30% throttle the LTFTs switch to 4-7% I have noticed. Only at idle and steady/light cruise when they go up around 9-11.

Old Geezer

iTrader: (3)

What Russ said^^^^^^^^^
We just had Vengence Tuning, [Mike Carnahan], dyno our latest project.
L92, mild cam, headers.
400/400 at the wheels. First thing Mike did was disable the LTFT's. And, they are still off.

danieloneil01

My LTFTs are turned off too but I use STFTs. Won't the MAF need to be recalibrated?