How can I fix this issue? on 1995 Saturn SL1

My car revs up to 3-4k rpms while idling then acts like it wants to die, and the smell of gas comes into the car. Plus, when starting up blows a white cloud out of the exhaust.

Asked by for the 1995 Saturn SL1
It could be a lot of things!!! Take your car to a mechanic and have it scanned, fuel pressure tested to find out what the problem is!! Cant guess at wrong every time!!! It will have troublè codes, find out what they are.....
Ok thank you!!! Hope y'all have a great night
1 more answer , 1 more comment
it could be one of the oxygen sensors or a bad air filter
Estimate on about how much the O2 sensors are?