1991 Oldsmobile Cutlass dignostic codes

I have a 91 Cutlass Calais. I have done the computer check for the codes. I have received many of codes. The code that I am at now is 4 flashes then 5 flashes. I can't figure out why is it running the way it does. If I'm not mistaking it means its running lean. What would cause this? I have replaced the Coil packs, Spark plugs, Complete tune up Injector, Ignition Module, Crank sensor, Throttle position sensor, Idle air control, Fuel pressure regulator, Fuel Pump/Harness, Fuel filter, Throttle body gasket, EGR valve, valve cover gasket, Cat. Converter and the computer is new also. When I bought the fuel pump harness the wires were reversed and ran my pump backwards. I had some problems before that happened but since then its running really bad. When I reset then computer it runs ok for a minute but I still have to clear out the fuel. I can't push the gas pedal but only so far. 2 days ago it started stalling on me whenever I went from park to drive or let it idle (even when sitting still at a red light.). When I bought the car it would stall on me once it finally would warm up a little. Once it cooled down for a minute. It has low miles on it. What is the problem with this car?