RB25 Backfiring, Sputter at WOT; Because of Open Turbo Elbow????

[FinkenS14]

Been having this problem for a while. Whenever I get into the higher rpms, the car starts to backfire, and sputter. Im on the stock 7psi, no boost leaks, no maf leaks, nothing. Brand new 02 sensor.
Could it be because Im running an open turbo elbow right now that is causing this?

Also my friend said an IACV problem might cause this?

Maybe even TPS?

Any help would be great guys, thanks

[monsta_civic]

double check of leaks, if you have a boost gauge that has a leak will cause this too(learned for xp) If everything else looks good clean your maf sensor with some cleaner, then ivac. then tps,(least expensive to most) but deff check for leaks because thats what it sounds like!!