Chasing down code 32 cannot figure it out?

I have been chasing down code 32, and I can’t figure it out. I replaced the throttle body that the shop had recommended. They changed that and I will say I seen a difference but still got code 32. Also, they recommended a MAP sensor which I changed. I changed the EGR valve put the same valve on from GM had it matched. I also seen the IAC connector was broken I guess when they pulled it off the old one the clips broke but didn’t tell me. I bought a new connector. Any chance this could be causing this issue. I am installing it tomorrow. I installed a new EGR purge solenoid. I erased the codes and still get code 32 when I drive. When I first start it up the RPMs go to about 1,200. I let it warm up and it dropped to 1,000. I shift it into drive it runs 750 to 800 RPMs. It runs fine. If I drive it and it gets hot and I park it and restart it. The RPMs goes up to 1,200 for a few seconds then tries to stall. Sometimes it does. Any suggestions? The only thing I can figure out is to clean the EGR port. I have the brushes anything I should use like carb cleaner while using the brush? Or maybe the cat is clogged. I will say I am pretty sure the cat is a problem but not sure if that has anything to do with code 32. I do have a new cat might throw it on this weekend see what happens. The only other thing it could be is the ECM might possibly be the cause. Maybe it is bad. No vacuum leaks I changed and checked all the hoses. A few were cracked but I changed them out. Thanks for any help.