

Backfire Sound:

Replace vehicles.awc 

in   mods\x64\audio\sfx\RESIDENT.rpf\

if you want to use this engine sound like in video:
go in any vehicle.meta and search the line audiohash/
and replace the line with this 

<audioNameHash>ratloader2</audioNameHash>
---------------------------------------------------------


if you have other sound mods inside in vehicles.awc,
use .oac export/import and replace the .wav files.....