Hello. Firstly, my car is a 1998 Peugeot 406 SV V6 3.0 liter automatic. In the morning, I start my car and start driving, as I have no problem in the first place, when it gives some gas to the car, it goes very well in 1st gear, but when it shifts into 2nd gear, a certain 2000-3000 rpm car pretends as if it is drowning. The engine of the vehicle is hotly reduced, no matter what gear it is in. Sometimes it gives beautiful performance, sometimes it doesn't. I do not understand there is an irregular performance situation. When the vehicle stops driving at traffic lights, sometimes when I park the car, if the mosque is open, there will be a wake-up sound similar to the expansion sound. I changed the newer oxygen sensor and potentiometer of my vehicle, the oil was renewed. I want to add a presentation. I do it myself a little bit with this tool, I changed spark plugs myself etc. I do not know why I put the manifold, when I attach the manifold of the vehicle etc. the vehicle performs very well for a certain period of time, but there is no continuity. I experience the same performance problem again after a certain time.