Heyy guys need help, when im at stop light my truck cuts off while in drive, it idles low when cranks up, it sputters like its not getting gas, I already replaced IAC valve, cleaned throttle body & mass air flow sensor, I replaced fuel pump,fuel filter,all spark plugs & bad coil packs, check battery & alternator, checked all vacuum lines & every now & then the check engine light comes on with a p220 code: Output speed sensor which I replaced, what else could it be

 

Year and engine type would help out bud.

Just to verify, the OSS on the trans was replaced already?

 

O sorry its a 2003 with 5.4Liter motor & yes OSS has been replaced

 

How did you test the alternator? I'd take a much closer look at that, if I were you.