I'd like to thank the people who stopped me from giving up on my Saturn.
My 98 SL2 had been acting badly, the automatic xmission behaving erratically, especially in slow-n-go/stop-n-go traffic.
I took it to a transmission shop, and he ran through the codes on the OBD and said---what did I know from the codes----that I was looking at a $4000 job on a car I paid $5500 nine months ago. (He told me to lose the car instead of repair it, obviously.)
A few people here told me that it could as simple as an electrical problem---bad battery (bad alternator?). Since the battery is a third the price of an alternator, I pulled the battery whose date was marked "Nov 2001", opened it up to look inside, and there was salt caked between the plates of 3 of the 6 cells! It was apparent when I jump-started the car, ran it for 20 miles (no red light indicating alternator malfunction), and the battery was still dead...that's when I pulled the battery. Must have been some cheap battery the previous owner put into it.
Now have a Kirkland (Costco says Everready is the same) 36/100 warranted battery in it.
Also corrected the transmission overfill (done in a panic) where I pulled out 2.5 gallons of fluid (previous owner had shop to a pre-sale inclusion of transmission "conditioner")! It now has new (Fram) filter with what took about 5.5 qts of (Chevron Supreme) Dexron III/Mercon. I hope that's acceptable. Did not buy the recommended-for-high-mileage transmission fluid at twice the price.
It seems to be running even better than when I bought it several months ago. I never would have thought a near-dead battery and a transmission fluid overfill could cause so much anxiety.
Note: I don't work for any of the brand names mentioned. I know that some people have a problem with certain brands, and their opinions are read.