1992 Pontiac Sunbird SE 3.1 engine causes it to jerk violently

1992 Pontiac Sunbird SE 3.1 mileage 135,000. 1992 Sunbird, with 3.1 replaced from a '92 Cavalier in 1999. Car starts fine, drives fine for a few minutes in the morning, however after a while any load on the engine causes it to jerk violently (I bit right through my tongue - ouch). Spark plugs changed within the last month. Had it to three shops so far, codes come up 32 and 33 My barometric sensor or whatever for the 32 hasn't been hooked up since 1999. Same with the lockup torque converter solenoid. Replaced MAP, seemed to work, until a few minutes later, same thing started happening. Happens at all speeds, 0-130 km/h depending on load. From stop, stalls frequently, unless I floor it, in which case I waste tire longevity, risk tickets, and when it jerks violently, it's worse than usual. They've checked for vacuum leaks, changed a few vacuum lines, changes nothing. Any help would be greatly appreciated, as I live 102 kms from work, and the drive is made excruciatingly long because of all the hills, and if it always feels like this, I don't want to bite through my tongue again.