shospecialist

hello, i have a 2001 nisan max AT, that i bought about 2 months ago wrecked. after two months of body work i finaly got my car back.Car had a real hard time starting and had ses light on, so i checked for codes and found that it has bad CPS. during the wreck the sensor and and the plug got damaged so i ordered new CPS sensor and found a plug for cps on the junk yard form a 92 maxima it looks just like the original one on 2001. so i cut the wires and instaled new sensor and the plug and car fired up like new no problems starting.I took the car to local shop for a interior detail and they somehow managed to use all the gas in the car, i mean they gave me car back running on fumes. so i took the car to gas staion filed it up half full and headed back home. On the way back home i got on it prety hard to se how fast it is and it pulled realy hard, then i slowed down and maybe half a mile later my car just died on me. towed it bak home checked for codes and it showed cps being bad.But i never reseted the ECU after i installed new one. so i took the batery cables of for maybe 5 min then put them back on and now car starts up and runs for maybe 5 sec then dies. so far i tried unpluging the cps to se what happens and all it does it makes my car start litle bit harder then dies again after 5 sec. i tried cleaning the maf didnt do any good i took the fuel pump out to see if it dirty or cloged up and i couldnt get it out of white box, but you can hear it run just fine, also when i start the car and give it some throtle then it dies instantly or revs for sec and dies very quick and sometimes you can hear poping noise like its back firing or something.Does anyone have idea what the problem, or solution is to fix my car. or just any onfo what to do next? thnx for all the help and sorry for the poor vocab.
ben