2003 chevy silverado 5.3L

Hi, I’ve got quite a few questions and looking for help/advice regarding my 2003 chevy silverado.

First I’ll start with some issues I’m having. Since I’ve owned the truck there has been some noise with the steering, whenever I’m turning the steering wheel it makes noise. I really don’t know how to describe it. Ya know, like “errrrrrrr” kinda noise. More so when I turn right. Also, the steering makes a knock sound while I’m in a turn and going over bumps. Before you say check fluid I have and put higher quality stuff in.

Another issue I’ve had since I bought it only happens during winter while it’s cold. After starting it the rpms shoot up but I’m guessing that’s normal to a certain degree, but as they fall it does this wanting to die almost kinda thing and the best way I could desribe it would be it runs like a performance cam would, with a lope but definitely not healthy and it’s stock so something is up. The check engine light comes on during winter and acts like that every time I start it cold. After the engine warms up it runs normal. Then when the weather warms up the check engine light goes away and doesn’t act weird after starting it.

Those are the issues I need help with and would appreciate any feedback.

Also, I have some questions about altering the stock exhaust. I bought some long tube headers and two 40 series flowmasters because I don’t want the restrictive manifolds on there and want to have a true dual exhaust. From what I know I’m gonna have to delete the cats and rear O2 sensors. And since it is newer that will cause problems. So I’ve heard there is a way to do this with O2 delete kits and stuff like that.

Advice on how to do this the best way and best parts for doing it would be a huge help. Thanks so much in advance.