1996 grand am 2.4 help

My daugther has a 1996 grand am with a 2.4. the engine has allways ran a little rough when we got it used. then one day the weather turned real cold (8 degrease) and had a hard time starting. I got it started and ran fine. I thought it was water in the gas so I put some heat with fuel injector cleaner in it. now the car runs real bad and it shakes the snap-on scaner said the number one bank is rich (I took the plugs out and the no.1 plug is black compaired to the other 3)and their is no respons from the catalitic converter (wich is starting to glow red). and a code s10 engine contoll unit. Is the injector just bad or is the ECM shot? please help I need to fix this asap and I am now unemployed so I don't have a bunch of cash to throw at this

Welcome to AF jeffmillard !!

Could have a injector or two bad and or stuck open causing it to run rich. Sometimes moisture sits inside the injectors and when its realy cold they'll freeze open or shut, causing simular problems.

Have you checked the ohms on each injector ?

How old are the plugs & other ignition components ?

Oh, and sorry for the delayed reply !

Thanks, I have changed the fuel filter and a bunch of black fuel came out and I have changed the idle air sensor, this helped smooth out the idle but still no real power. I also changer the plugs gapped to .060 and the boots from the coil pack, as well as one of the coils. ran it for a few minutes and check the plugs no fun in 15 degree weather. the #1 and #4 plugs clean and a little wet and the #2 and #3 black and dry. I also disconected the exhaust pipe at the manifold to check if it was a plugged cat. made no differance. What ohm reading should I get? as I am now leaning this way, as we recently put heat with fuel injector cleaner in it and the daughter did not put gas in right away.