"Blow off" sounding squeak?

New to the forums, this will be my first ever post. But me and my homie just installed a borla s type cat back on my 2008 tacoma. Everything sounds great but when I let off the gas every time to shift (6spd) it makes this quick little squeak almost as if it was purging the back pressure like a blow off? He was telling me it's normal and that the tacoma practically has a blow off type system that is now more present with the new tones of the new exhaust. Has anyone else noticed this? I'm just trying to get a second opinion on whether or not it's normal, the homie is a smart man but sometimes I question him lol. Any help is appreciated

 

" The Tacoma practically has a blow off type system that is now more present with the new tones of the new exhaust."

What does that even mean?

 

Troll account.

 

Nope. You have a leak or something. There's no blow off valve. Only time you should hear an air chirp is when you turn it off you might hear the emissions purge valve under the hood.

 

Lol this isn't a troll account i'm being serious, he says it's just a release of the pressure but I thought that sounded kind of odd as well.

So you think I should tighten the clamps and bolts a bit? Hopefully it's not a crack in a weld or something that isn't able to be tightened.

 

Homie don't play that shit! LOL

 

I would say if you and your homie hear this "squeak" after going through a taco bell drive-thru, it's not the truck's exhaust but it is a "blow off valve".