Cam gears question.

I have a '94 prelude Si with, headers, Apexi exhaust, AEM cold air intake, AEM pulies and AEM cam gears. My problem is that my cars timing is always getting off. I have a hard time turning the car on and alot of black soot comes out of exhaust. Recently when the car is on I hear a knocking in the engine. I took it to a mechanic and he said it was due to the cam gears, that they were getting the timing all goofy. He said the only way he would fix it is to install the original cam gears. My question is how much difference will my car be without the gears. :crying: