My niece has a 1999 SL2. It is intermittingly losing power at high speeds and dies at stop signs - but again intermittingly. The "Service Engine Soon" light does not come. The fuel pump and filter were changed in January and the front O2 sensor was changedthis week. Does anyone have any idea what would cause the car to lose power (not die) at 65 mph and die at stop signs, but only do it intermittingly. Yesterday it ran perfect - today it lost power going down the interstate.

Does the car sputter and then die as you're coming off the highway?

I had a similar problem w/ my 1995 Saturn a few years back. On the highway, it lagged a bit, and when I was in more stop-and-go traffic the car would sputter a bit, the RPM's would jump and fall, and sometimes the vehicle would just die.

We took it to the dealership and the technician said that the throttle body was clogged preventing the proper amount of fuel from being burned. I didn't see him do it, but apparently he either emptied it or replaced the piece (~$20). Bottom line: the car worked fine afterwards - never died or sputtered again, to this date.

A friend of mine had a similar situation with his 1997 Saturn, too. Perhaps this is what's hindering the power in your niece's car. I can't help but thinking "common trend among Saturns." Hope that helps.

I have a 98 SL2 and intermittantly would not start. All I would have to do is sit and wait a few minutes and it would start. Changed a bunch of stuff like you. Saturn mechanics did not have a clue. Turned out to be the crank shaft sensor. Edited by: Richdc