dodge 4.7 fuel trims

[Scottyb_288]

anyone in here tuned a Dakota or Durango or any other Chrysler product with a 4.7 v8? just curious on whats going on with the fuel trims. tuned one a few days ago and literally had like zero error from upstream o2s as far as LTFT correction. it was 0 for the first 15-20 minutes of the drive and there after there still wasn't much of any error. judging by how the VE and timing tables looked I cant imagine theres zero error from the factory lol. is there something I'm missing? attached log and tune.

aarons truck ve final wot adjust closed loop fuel trims.hpt
aaron fuel trim scan.hpl

[Blue Bee]

Hey Scotty I gave it a look, what all did you tune on this truck? How much have you changed PE? Stock this is a VE setup so I'm sure it really is dialed in pretty good, I see you are commanding 12.5 AFR at WOT, back in the day from what I remember with NGC4 is it looks at STFT and if it's above a certain % for X amount of time then it makes the change in LTFT, and your STFT are not that outta whack. I don't think you are missing anything but the question is the fuel where you want it on a wideband?

[Scottyb_288]

I smoothed VE and timing because they looked like the rocky mountains. Lol. Added a tad of fuel in WOT to hit my commanded AFR. And adjusted VE based on the fuel trim errors in each cell. Adjusted other things such as Stoich FA(set to 14.7), and PE(to command 12.5), and changed throttle response. Didnt get into the trans as ive not done one and im 100% not going to guess on a customers vehicle. Would rather guess on my own. Trying to find some info on tuning the 545/45rfe before i blindly adjust. But yes fueling ended up how i wanted it on wideband. Customer text me a few days later saying he was getting p0174 which is bank 2 upstream o2 reading too lean(in refrence to fuel trims not AFR).

[Blue Bee]

I'd do another log/drive, I noticed on the log you posted there is no B2 Voltage, make sure to log that and see how that sensor is switching. You might even just have a drifting O2, how old is it? Vehicles that have 50...60K miles and up, I pretty much make the customer buy new O2's. It's cheap insurance, especially for the guy tuning. Don't want to get wrapped up chasing your tail over a failing O2. It's only bank 2 (for now anyway) popping the DTC.

[Scottyb_288]

Vehicle has about 120k miles. I will run another log and report back. I appreciate you taking time to look at the log and tune and provide your feedback.

[FlyinRyan]

I've tuned quite a few of these 4.7s over the years with SCT. They usually don't need a ton of work on VE. Set your PE, play with timing, and you're golden.

The last NA 4.7 I did made 312 whp on a stock bottom end and stock heads.!!!

[Scottyb_288]

Good to know. Thanks for the input guys. Gonna try to run a log this weekend to see whats up with the bank 2 upstream o2.

[Scottyb_288]

Customer replaced said o2 sensor and cleared the code and the light came back on within 2 days of driving. Starting to wonder if its mechanical issue with truck.(vacuum leak, exhaust leak,etc)