99 gtp stalling, just shutting off

hey eveyone i got a 99 gtp it keeps stalling out then its hard to start.
i replaced the plugs and wires and fuel filter it stopped for a day and now does not do it as much.the sevice engine light has come on and abs but when i hooh it up to the scanner no codes come up.have all updated hardware for scanner and i'm a autobody tech can uasually figure it out but not this time help me guys i don't have money to keep blowing