I have a 96 s32o and I have that kind of problem; rough engine run. this happens when i exceed the 3.5K rpm during acceleration and the'check engine'light turns on. I get a PO3 missfire on the diagnostic report.
a quick fix that i do is to turn off the engine and restart. the check engine light remains but the rough run goes away. to turn off the check engine light, i simply erase the report from the car's computer w the OBD tool.
I hope this helps.
As for this problem, is there anybody who can tell me why this is happening?
thanks.
t2p