rough running rodeo

my 92 rodeo 3.1litre with 4 speed auto tranny is running rough.when warm rough idle,under load it bucks ,hesitates stumbles,like not enough fuel getting to tbi,,getting code 44 from ecm,lean exhaust,changed,distro cap,rotor,plugs,wires,pcv valve,O2 sensor egr valve,map sensor, tbi gaskey fuel pump relays ,fuel filtre,checked fuel pump,ok,had tranny shop check tranny,they say i need a new main arm for shifter,7 to 10 days for part to arrive,could it have anything to do with poor running condition?also checked for vacuum leaks,none found.any thoughts on what to check next?