Hey guys, new to the forum and I like it. I have been chasing a ghost in my 04 trailblazer. I recently changes the cracked exauhst manifold but didn't change the o2 sensor until about a week later. I went out of town for my daughters doctors appointment and noticed it stalling at red lights and was surging when I took off. Once you were going it would run fine. I read some forums about cleaning the throttle body and so I did that and yes I unhooked the battery. Now the engine idles better but when you first start driving it kinda falls on it's face stalling put picks back up and goes. It only does this with the ac on and before the temperature is at operating range. No codes. Also since i unhooked the battery I am also chasing those stupid ac door motors. I'm about to get that worked out. If you guys could help on the stallin I would appreciate your time