Hello, I'm having a very hard time figuring out how to get the boost to not fluctuate like crazy on my friend's Cobalt. I'm wondering if there's something I'm overlooking.

I tried zeroing out, using stock, using what was originally on the tune, going up, going down etc on the closed loop boost tables and it doesn't make a difference. Is the desired boost DC on scanner not the true output? The throttle is sitting at a solid 82-83% through out the pull. The boost doesn't fluctuate when I set the DC to 0%, it'll hold about 18psi. Sometimes it'll hold fine and sometimes will go up and down up to 5 times in one gear by about +/- 2psi. Duty cycle is set to around 48% until 4k then ramping to 60% at 7k. When it works right I see 23 down low and 26 up top.

The original tune on the car was very weird with the throttle controlling the boost and seeing a 10psi difference between ic piping and manifold pressure. It didn't have a fluctuation before, but it's possible that was masking it.

If I need to post a log or tune file I can in a little while and I'm on my phone right now.

The car currently has ZFR 7163, ZZP HPFP, 5th injector setup, E85, 3" Catless Exhaust, IC & Piping. The car has the fueling to work well but the boost is just confusing me. Maybe I'm not understanding the boost control correctly. Please let me know if there's any suggestions.