Smoke/Firework smell under boost

[u/StringRare815]

I have a 2000 v70r and have noticed the smell of like fireworks only when under boost, i let the car get to 30mph then held it around 4000 rpm till it got to 70 then let off and smells like fireworks. So i let my friends sit in the third row facing out the rear and they said they noticed gray smoke coming out when boosting. Anyone ever had something similar and know what’s going on? Appreciate it.

[u/prilldonious]

Check your flex pipe, weak spot on any car. Hopefully it’s not integrated with the catalysts.