Sputters and dies

When driving at highway speeds for a while then coming to a stop the RPMs wiggle up and down and then the engine dies. Does anyone have any idea what is causing this or have you had this problem?

I'm posting this WAAAAAAAAYYYYY too late, but I've never experienced this problem with our Silhouette. But it's an Olds, so anything is possible... :o

It turned out to be the oxygen sensor.:(

Can you tell me more i am experinencing the same thing on my car also my engi light stays on. how much was the oygen sensor and where did yo9u get it put in etc... helppppppppp

I have been having the same problem and my check engine light is on too. I took it to a mechanic and he told me the Ignition module was out and the comp. was out. He replaced the module and that did not fix anything. I have not replaced the comp yet. That brings me to my post what is the comp called or a part # ??? So I can see if I can find it cheaper on the net. My next question is any sugestions on where to find it? Thanks Joker55.

IT turned out to be a faulty catalyc converter, Luckily it is still covered under the manufactors warranty under a clean act law. Most mechanics and dealers will not tell you this. I was at pep boys and they were ready to charge me for this $600.00 but i bought an extended warranty over the net and called them and they informed me that they will not cover this item because its a dealer covered part. Hope this helps you all. Once it was changed car ran fine and i changed the oygen sensors too for good measure.

You will find warranty coverages listed in your owners manual.
On most GM cars, catalytic converters and PCM's are covered under a 8 year, 80000 mile factory warranty.
Most aftermarket repair facilities are not aware of warranty coverages. Had you had your vehicle diagnosed and repaired at a GM dealer, the converter would have been replaced at no charge to you.

Also i originally bought the car to a GM dealership 2 years ago when this first started they charge me a fortune to tell me there was nothing wrong...
it was replaced at no charge at a GM dealer, but i first went to pep boys for inspection and a oil change. it didnt pass inspection due to the converter malfunctioning. afterwards i bought it to a gm dealer and they fixed it, it took 3 weeks. 2 weeks for an appointment then another week they kept the car order parts and installed. way to go GM dealer...... they didnt even get me a similiarreatal car as a replacement they rented me a compact car. they had my mini Van which seats 7. compact car seats 4 maybe five. I had a plan trip to sesame place that weekend and had to take 2 cars. Way to go GM dealers....
While they had my car they also pulled off some side molding which they denied, they wouldnt fix it but recommedned a mechanic who would for a small fee. Way to go GM dealersssssssssssss nuff said. The converter was covered under a clean air act law not under anything that GM has. Way to go GM dealersssss. ok now nuff said.