I replaced my egr vavle and there is 2 holes on the back of it. There is this plate that covers them both up and a screw that holds it down. When the car is running, exhaust is puffing out of it. I pulled the plate and screw off my old one and went to put it on the new one but the screw isnt the right size. Do I need this to be on there or can I leave it off. I guess there is suppose to be a sensor on there but mine didnt come with it or what? Can I weld it back on?