Problem with my v6 vortec spends a lot of gasoline

I need someone to help me find the fault to the S10 only give me 4km/l urgent !!!

Hey, we're not mind readers. Explain the problem a little better so we can help you. There are hundreds of reasons that can cause excessive consumption

Look, when I try to start the engine, it starts on the second try. Once it starts, it idles smoothly. When I accelerate, it runs normally; it doesn't knock or shake, but the temperature gauge rises to a little over halfway, and the car feels sluggish. Also, if I brake and accelerate simultaneously, it doesn't jerk anymore. Another strange thing is that even with a cold engine—I'm talking about driving about 500 meters—if I open the radiator cap, it releases a huge amount of pressure, just like a hot car. Anything else? Honestly, if you can help me, that would be great, and feel free to ask me questions; it'll make it easier for me

Check the exhaust pipe, loosen it and see if it improves. That just happened to me and it was a clogged exhaust pipe

The tube? Or the catalyst?