Hooker Blackheart NPP Exhaust
Thread Starter
Heel & Toe
Joined: Apr 2022
Posts: 22
Likes: 2
Hooker Blackheart NPP Exhaust
Having an issue at low rpm where the NPP valves are not staying shut. If I stab the gas they will shut but then slowly reopen again. Driving they stay shut so I'm guessing it's a loss of vacuum. Idle is somewhere in the 750-850 range. Previously had stock npp exhaust and zr1 mufflers and did not have this issue.
Any input or suggestions are appreciated.
Part # 70401313-RHKR
h/c/i z06 for reference.
Any input or suggestions are appreciated.
Part # 70401313-RHKR
h/c/i z06 for reference.
Last edited by bsikich; May 12, 2025 at 12:50 PM. Reason: Forgot to add something.
Thread Starter
Heel & Toe
Joined: Apr 2022
Posts: 22
Likes: 2
Turns out one of the small vac hoses that hooks up to the actuator had a small hole in it from all the alignment issues I was trying to fix. Must of been to rough on it. Replaced it and the valves stay shut now at idle. Alignment could still be better for 2 grand...
