if ignition control module is bad, would it make my truck run bad ?

I had a similar problem. Our truck would not stay running unless you kept the RPMs high. It would stall out if you took your foot of the gas while slowing down. I replaced the Ignition Air Control Valve. It is located on the back of the air intake. Part was $55 and it took me about 15 minutes to change it. It only has 2 torx screws holding it in.