Ever since I changed to my LT's and Bassani catback, my engine seems to bog down between 35-50 mph, like I have to really step on it to get it going again. Maybe theres a slight blockage somewhere? I thought the bolts were loose but I checked them and they were all tight. Funny thing is, it's coming from the driver's side right in the area where the header is. Any suggestions? What is that bronze pipe that connects to the outside of the header? Could that be it? Please help

 

you mean the EGR?

 

That's the EGR tube, make sure it's tight. Check your plugs too.