Well while I was getting my neo tuned it started making this suction noise over 5500 rpm's like it was a vacum leak from hell. And it was LOUD. I asked what it was and they said nothing. But now off the dyno driving around I can here it over the wind even. Just a LOUD ssssSSSSSSSSSSSS sound only when gettin on it though. But It was never doing that before, I dont think.

Any suggestions

 

Check your air filter...maybe it came off?

 

maybe its an exhaust leak.

Or maybe you have xs headers and theres some resonance that you never noticed outside of your car

 

Could be your thermospacer. When I removed my Thermoblok, it looked like it wasn't fully sealed. I was getting a whistling noise that I didn't care for.

 

Can that cause loss of power?