Lq4 stumbles and stalling

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Did a mild tune on stock 04 Denali and after a couple weeks started ruff idle and stalling. Reloaded stock tune and same thing so started checking for other issues. Runs fine with mass air unhooked so replaced with a good one from my other truck and same issues. No codes and intake gaskets were done 2-3 years ago.

[Ben Charles]

Check plugs... that will tell you what?s going on inside engine

Scan fuel trims and see if they trim similar

[IARLLC]

Like Ben said, "fuel trims". If it is running OK without the MAF I would guess that the MAF settings are a ways off.

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fuel trims were a little out so I pulled the intake and cleaned it up. block sanded intake surface to ensure it was flat and installed new felpro gaskets and injector orings as a just in case. Now the trims are in range and runs much better but still has a light stumble and will stall after a few minutes but fire back up fine. it has the factory tune in it.

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After driving it 20-30 miles and dealing with multiple stalls trying to get a good data log it has started running perfect. Not sure what was going on. Put tune back in it and all is still good.