help i hear knocking sound

hey fellows

i have an Aqua/prius c 2012 . In oct 2018 i planned on getting the engine tuned as it has been a long time and i felt there was need to get the throttle body cleaned . So the person i handed my car decided to clean the injectors and throttle body aswel , so here is what happned

The engine got noisier after that , and the engine keeps knocking and clicking when driven on medium acceleration , something like this

and there is this clicking sound when the i start it in the morning and sound reduces after driving for like 10 kms .

second sound i hear is , it feels like the exhaust pipe is leaking. i have shown it to a couple of mechanics but they couldnt figure out whats causing it

help

 

hi bisco its 76000 kms