I have a 2004 mustang cobra with a bouncy idle and slight surge when cruising at about 2000 rpms. It idles great tell its warmed up and if its warmed up and i turn the a/c on the idle smoothes out. I have had a smoke test done to check for leaks,new 02s,new iac, new tps, cleaned throttle body, cleaned mass air sensor. Another thing is i am throwing a po171 code and po174 code which are lean codes. My aem air fuel guage is all over the place and under wot it just maxes the fuel out but when just cruising fuel cuts out but then maxes every once in a while and im getting terrible fuel economy. The mods my car has is 2.8 upper pully with a 2 pound crank pulley, 60 pound injectors, sct 2400 mass air sensor, cai, two walbro fuel pump setup from lethal performance, Solid rear axle, spec stage 3 plus clutch, with a built t-56 trans. Any help to this problem would be awesome cause im getting really frustrated with it Thanks
