i have a 95 200sx runs good until i drive about 20 to 30min starts smoking grey and stalls if i let it sit about ten min it starts to run fine for another 20 to 30 min not overheating and has 150 psi of compestion can anyone help

it could be your catalitic converter? is this a manual or auto tranny? if auto sounds like it would be your tranny module? i think converter?