I have a 93 850 5speed sedan. Runs like crap for a long time and running out of patience. Car kept randomly stalling. Suspected fuel pump and replaced it. Car drives fine for a while and then will suddenly stall w/o restarting for a minute or two. Replace fuel relay. Seems to have corrected stalling but car still ran like crap. Check engine light came on. Pulled codes 4-1-3 and 2-1-4. Replaced rpm sensor and mass air flow sensor. Checked fuel pressure. Car ran great for less than half a day. Now pulling same error codes. Now what? Could these same 2 sensors have failed in less than one day? Please help. Ready to burn car!!