P0174 and log eval - 5.3 Silv 4x4

[sredish]

2010 Silv, 5.3 4x4 6l80, Long Tubes, Cat delete, CAI

Got p0174, was hitting open loop and dumping fuel. Found leaking exh gaskets and replaced plugs. Completed comp check, pressured smoke check, scoped inj and valves, cleaned / flushed fuel sys, tested new MAF, intake cleaning, all 100%.

p0174 has popped up once afterwards right after fix. Reset, didn't come back on. Thinking truck needs to be driven. Took for drive and code didn't show but still comes up in permanent. Truck runs and drives great, plenty of power and is currently in CL.

Tune has been the same for 5 years with the exception of the cat delete 2 years ago but same tune. It has some gear setup idle changes for different reasons, offroad truck with deep gears. Has some throttle changes as well to try and pull a little response out. Any chance of a review and the latest log run to make sure I'm not missing something?

Forewarned, there is no wideband on the truck currently (on the list). Below log goes up to 75% throttle and being that it's a basically stock truck, not a lot of craziness with fuel tuning as it is.

Thank you!

Vid for context: https://youtu.be/UCaUA9Yq4Zw?si=xw9CzEK_A8ZjdwXR

120624last.hpl
Silvi_Current.hpt

[blindsquirrel]

I find it hard to believe you did all that work and didn't check fuel pressure, yet fuel pressure isn't mentioned.

You cleaned the MAF, but MAF isn't being logged? How would you know if the cleaning did anything?

It is still lean. O2 traces are biased low - meaning, they spend a lot more time down on the floor than they do up top, and the floors are long and flat, then brief spikes with pointy tops when it does finally go rich. Check the fuel pressure. It's the same on both banks despite P0174 being for B2 only. When it's no longer broken, O2 traces will spend the same amount of time lean as they do rich, and the upper parts and lower parts will be the same shape.

Once a code is set as Permanent it can only clear itself after a certain number of drive cycles, but that is not why it's still lean (think of a Permanent code as another level in addition to Pending, Current, and History - it's like Super History).

[sredish]

I find it hard to believe you did all that work and didn't check fuel pressure, yet fuel pressure isn't mentioned.

thanks dude. you're right. we did check fuel pressure but forgot to state. was 70 at startup and 52 to 58 once going. need maf on there, guess i overlooked that as well.

pretty positive the lean 0174 was the exhaust gaskets but i understand what you're saying with the o2s.

[blindsquirrel]

Plus, trims are having to add ~20% on both banks all the time. Even with that you can still see it in the shape of the O2 traces.

2010 Silv, 5.3 4x4 6l80, Long Tubes, Cat delete, CAI

But a stock untouched MAF table in the tune file...

...and oh look at that, VVE is untouched, too.

[Alvin]

It could likely be corrected just going over the MAF table.

The CAI you used will need a different MAF calibration. Also MAF's degrade and foul over time. Cleaning it might be a good first step.. but this is pretty easy tuning 101 stuff.

[sredish]

gotcha guys. i'm getting to work on getting some of this cleared up. thanks.

[sredish]

Got the MAF a little more dialed in. Thanks for the direction. Going to work on VE a little now. Did a light adjustment and some smoothing and will start zeroing that. Need to get a wideband on the truck before I can get too much more wild I feel like. o2s look a little better to me. brought PE in a little earlier as well.

Silvi_MAF_9_VE.hpt

120924_ve1.hpl