lean condition on decel.

[Rad_richie]

First off, I'm as green as it gets with efi, and tuning so bare with me. I'll include a scan I did that tries to replicate some off road driving and a regular scan with freeway and city driving.

Background: 2004 5.3 swap into 1990 bronco with shorty headers , Y pipe into 3" back with no cats, 4'' intake from a large intake for off roading. that's it as far as mods go.
I have put over 3k miles on it in the last few months since shes been built. from 2000ft elevation to 9000ft. about 800 miles have been off road. I do not plan on adding a turbo, and I don't plan on any WOT pulls.
I'm having trouble finding information on how to even do a basic tune to fit my needs. I have a wide band from my other car, but I cant get it to work because it doesn't have a 5v reference wire. its a custom speedhut one a bought a few years back with a bosch 4.9. [maybe someone has a work around for me.] I tried using a voltmeter and found a wire that seems to be what I need, and tried tying into pin 55 on my ecu, but no dice.. I can not find the egr enable/ disable function within editor. p59 ecm

ok....so last weekend we went up to about 8000ft throughout the trail and there was a lot of deceleration on the way down obviously... full of pops and such which has been normal, but the vehicle started smelling different from the exhaust [ back window was down ] this lead me to want to try and figure out the tuning finally.
I grabbed my afr gauge and hooked it up. it runs 14.7 for the most part of normal driving. It doesn't ever get past 13[ stock tune] while trying to replicate some offroad driving and decelerating it runs up into the 18 range. this type of scenario is super normal on all the trails im going on, and places ive been driving to.

I want to start tuning it, and I'm overwhelmed with info from forums and videos. I was going to try and start with MAF tuning, but I cant seem to find a suitable lesson to follow since I cant get a Wideband hooked up.
Now Ive read about DFCO, and I wonder if I should start there to start dealing with the lean issue I have while decelerating.

any help is greatly appreciated.

off road simulator decel lean.hpl LongLogFileWithFreewayandStreetDrivingBeforeTuning.hpl

[5FDP]

Decel fuel cut off turns the injectors off, that is why the widebands reports lean because there is no fuel going into the cylinders.

If you log your o2 sensors and injector pulse width avg's you'd see this as well.

Parts of the fueling need attention as the fuel trims shoot up to 20% at part throttle. Double check that there are no vacuum leaks/exhaust leaks and that fuel pressure maintains 58 psi.


The EGR enable/disable would be in the exhaust tab if it has one or it's found through the Navigator under the edit tab if you are using an older version of the software. The newest software made the exhaust folder it's own tab in the engine side.