5.3 running lean

[Darkcloud]

Hey Y'all,

This is my dad's truck. Stock except for k&n intake tube and 285/70r17 tires. I've never looked at a good running stock tune truck before and was wondering if his truck is running too lean or if this is normal for stock truck. All exhaust bolts are tight/not broken. No intake leaks. Fuel pressure is 58psi idle and 61-62psi at 3k. O2 look to be switching properly. Cleaned MAF and TB. Truck does have a intermittent P0446 code. Could be purge solenoid, charcoal canister, cracked evap hose, gas cap. Could that cause a lean condition? I know in Chrysler stuff, older stuff, evap issues would cause lean/rich issues depending on what pat of the evap system failed. The only other thing I have not checked are the cats. Probably run log the rear O2 to see if they are flowing properly. What ya'll think?
22-09-10 20-10-17.hpl

[5FDP]

Looks totally normal to me. Really only has one spot in the rpm band where the trims liked to stay around 10% but then they came right back towards zero when it was out of it. That is well within the computers ability to correct it, so it's never really running lean with fuel trim corrections.

The P0446 is specific to the vent valve, it's in the description of the code. It's a super common failure on those trucks. Will it help with the fuel trim, hard to say for sure.

A truck that old could have the injectors cleaned up and new o-rings installed to make sure the injectors are flowing correctly and that there are no leaks once the intake is under heavy vacuum. But otherwise if there are no lean codes, it's not really an issue.

[Darkcloud]

So, I ended up talking him into doing a 6.0 cam swap it with lq4 cam out of my 3/4ton I did the truck norris cam in. Did the cam swap and did a weeks worth of drive tuning to it. Also did a vette servo in it. Dad is back in his muscle car days ha. Did the cam swap, loaded lq9 spark table in it, changed power enrichment set points, took a small amount of TM out, set the tire size, upped shift speed and boosted line press. The VE and MAF are 0 to 1 range. From the logs, seeing the delivered torque numbers, saw 35-40lbft difference. Kind of surprised at the amount, I know it is not a true output measurement. Truck definitely has more kick to it now. I really like the trans shifting now, not more slow lazy shifts.