need help
 

im 17 i got a supra was running fine didnt have power steering though that didnt bother me it was idleing low so i took it to my mechanic who used to work on my beastial dodge ramcharger and he said clean out the throttle body so i used carburator cleaner and it deepened the sound of the car this was 2 weeks ago this week,last week the car droped even deeper and in the past two day a LOUD knock started occuring at all times when running i dont know if i should rebuild or take it to a mechanic to fix, and if i do need to rebuild i cant pay for it in a shop is there someone near me with experiance cause i was only taught to rebuild dodge motors like the 318 360 and the 400 wich are identicle with diffrent headers