My mom had a 96 olds Cutlass with the same peice of trash 3.1. I swear that thing eats an $80 injector every 6-12 months. Thats the best part, try getting to them! You have to remove the intake which is a cool battle! The car itself is in general a cheap POS that my sister is currantly running into the ground.
Our solution was to buy my mom a 2007 Rav4. So far the Toyota is flawless, as expected.
The trick with the back three plugs on these POS engines is to put 100K mile super platnum plugs in. Then just never change the back three, figure the car's going to die first. Plat plugs should go 150k-200k before they miss fire.
I say dump it, its a sunk ship let it die. Buy a nice Honda, or Toyota and enjoy.
The new Camry is out and its an amazing car if you want to shop new.