Need help- 2007 mustang part throttle misfire/popping issue

[ChristopherRPark]

Working on a 2007 GT with long tubes, FRP intake manifold, comp mutha thumpr cams, bbk 62mm TB and some no name CAI.

The car runs beautiful everywhere except between 2-2700 under heavier load, like 4th-5th gear in this range. where it pops and bangs an lean misfires until you bury your foot. Ive tried all sorts of tweak in the maf V range it does it in, about 2.0 - 2.7 volts to be exact. Ive tried throwing a bunch more fuel at it,only to have the trims take it right back out in that range. The car works great at WOT, it made 356 at the wheels and maintains a nice 12.8 AFR. When it pops/farts it goes into the 18's for AFR and you can hear/feel it bog, even the o2's you can tell go lean... Doesnt seem to matter how much i wack the maf table with extra fuel right there.

Anyone battled this issue? Is the no name intake causing turbulence around the maf? The maf cartridge is stock too. The maf housing is cast alluminum if that makes any difference and uses the stock rubber accordian hose to the TB.

ANY advice or help is appreciated!

I attached the tune and log of it acting up.

Attached Files Attached Files

File Type: hpt o7regencymodded.hpt (704.7 KB, 20 views)
File Type: hpl regencystumble.hpl (18.1 KB, 9 views)

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[Daox]

Have you tried putting the stock intake back on it to see if it fixes it?

[parallelevan]

My old 5.0 ranger had a similar problem it was at alot lower rpm tho 1500-2000. Once I finally took the intake off I noticed it had cracked when I tightened it down
It was letting unaccounted for air into my intake after the man causing it to lean out and backfire

Verify torque on your intake gasket and hoses make shure you don't have a leak