Hi to everyone

I have 94 Honda Civic with 1.3 D13B2 engine, i have changed timing belt around 100k kilometers( now is on 110k) but the guy who done the belt didn't place it corectly and the engine worked roughly, i drove like that for 200-300 km before i fixed the timing belt issue, other guy placed it corectly but now i have another problem. I know my car very well, before i changed the belt i couldn't hear the engine at all, neither I was feeling any vibrations in the car, now however, the engine does not run smoothly in idle and my top speed is limited to lets say 140-150 kph( before it was going up to 200kph) i feel more vibrations through the shifter, steering wheel and windows. In this state which is now my engine it splited the fuel consumption lets say by 30 % less fuel and sometimes when it runs in idle it kind of misfires, i hear 3 same explosions but the fourth one is different. I want to ask you what is your opinion for my problem, and how does lambda sensor corrects the fuel-air ratio on this type of carb, is it by vacuum and how to check if it works properly? I checked the belt several times with different technicians and all of them said that my belt was aligned with the marks so it was not the belt.