Well, I change my stat and that fixed my issue of it being rough when stopped and not getting up to proper temp. Now I am having a issue when my blazer is cold it feels sluggish in first gear. Once it gets up to around 25 mph it is smooth. Also once it gets up to temp it is fine in first going slow. When I accelerate after my car was just turned on it feels like something is choking my motor. Now I just had the fuel pump change and the fuel filter. Also just changed all spark plugs, wires, cap and distributor. Also just changed the air filter as well as an oil change. Tranny was just serviced and catalytic converter was replaced. One thing I was originally thinking was when I had my cat replaced they showed me the old one and told me all the inner part was in my muffler because the cat was completely hollow when they pulled it off. Now I have not changed my muffler yet because I just havent had the time and up until the last couple weeks had no problem. I dont think that is it because like I said, it only happens when my blazer is cold. Thanks for any help.