when i bought my 93 rx7, the engine shake alot. My rpm will rev around 700-850 during normal idle. If i rev the motor, it stalls really bad when it climbs back down around 1500rpm and below. I have done couple of maitenance like: spark plugs, coils, oil, air filter, fuel filter, etc...

Could a bad 02 sensor cause this idling? Anybody out there have a similiar idling problem? Please Help???