New Tuner - 2014 Stock Silverado

[Salvin]

I am working on tuning my over 200k mile stock 2014 Silverado 1500 L83 5.3L. It is a stock truck with an Exhaust on it. I have an MPVI3 and an Innovate LM2 wideband that I have built a decently accurate MAF tune with while learning from both here and Youtube.

I have also done some small things, like disabling DOD and changing some TCC lockup settings as recommended by a lot of sources for these pickups.

I began what I felt was the next step, which would be tuning a VVE/Speed Density map. I disabled DFCO, forced Open Loop, disabled MAF as recommended in Goat Ropes Speed Density process. I put some miles on doing quite a bit of logging with the stock VVE table to gather data. Once I gathered and reviewed the Log I felt that I should do a bit more research before I implemented the changes to my tables as some of them seemed relatively dramatic for a mostly stock pickup. I tried to clean up the data a bit. I set a filter do only show data greater than 0% accelerator pedal position, as well as a filter to discard anything over 1.2 EQ on Lambda, just like I did with my MAF tune to filter out of a lot of the lean on decel readings. I still have quite a few tables that were over 15% rich on the higher RPMS, especially at low MAP Pressure. I have PE enabled, but it seems the common recommendation is to Tune with PE enabled.

If someone could please look at my logs and recommend how I should proceed I would greatly appreciate it.

Do I implement the changes from this log and begin tuning? Do I skip VVE tuning on a stock high milage truck like this and move on to Spark tables?

Thank you for any responses, I have attached the Log file and the Tune I used with it.

[JASON11WS6]

The LT motors like to be VVe tuned as well as maf tuned so it's a good idea. What was done to the truck? The afr doesn't seem to far off but if you have a good data go ahead and update it.

[Salvin]

Thank you for the reply. The truck is Stock with over 200k Miles. The only modification is a full exhaust, but I may add a Cold Air Intake in the future.

[GHuggins]

You might want to put a set of injectors in it and do an induction service. All your tuning is doing is working around mechanical issues. Exhaust from cats back shouldn't require changing the airflow tables. These things are notorious for injectors wearing and overfueling - usually see them 10 to 15% rich by 140ish K miles. Now if you put headers on it, there are some changes that need to be made, but otherwise you should only have to add some power and response to the stock tune - not do a full tune so to speak... Also keep in mind the muffler setup alone on these is worth a couple degrees of timing and stock can a lot of times be better. Usually just remove the third cat and the right muffler back and your good for some extra...

[Salvin]

Alright, thank you. To be forward it is a clean 425k mile fleet truck, the motor and tranny both appear to have been replaced sometime in that period. The cats were plugged when I got it so, while it is free-flowing, it is technically a stock exhaust. I will look into replacing the injectors, thank you.

[GHuggins]

You'll need to make some minor changes for the cats, but still shouldn't need a complete rework tune so to speak.

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You'll need to make some minor changes for the cats, but still shouldn't need a complete rework tune so to speak.

I'm in almost the exact same boat, I'm trying to sort-out my new to me 2014 Silverado L83. Mine is about to be Cat-less, the replacement cost of these cats are insane, any advise on the OEM exhaust? How restrictive is the original muffler and resonator?