I want my MPGs back
 

My son just returned from a deployment in in Okinawa, and has pulled the 1997 SC1 out of storage. He has noticed the gas mileage is way down from when he left 7 months ago. He put in a new set of plugs and wires. I mentioned that the O2 sensor(s) may need to be replaced (they are original and we had seen a code for them once before).
I wonder if the ECM needs to be reset? Anybody out there with any thoughts. He is in California (Mohave Dessert area) and the car is a Michigan car...

If he put in NKG plugs he did no harm. Now if the car has been stored in the desert and didn't replace the air filter then he didn't do the first thing that should have been done before starting the car. No reset needs to be done just because the car is from Mi. Where in the Mohave is he?

Aftermarket 02's are damn near worthless get from the dealer. Any odd temp readings or if the cooling fan does not come on at the 3/4 mark may need to replace the ETCS and connector. Two more items that should be bought from the nearest GM dealer servicing Saturns.

Thanks for the input. I'll ask him about the filter and plugs. The engine was rebuilt at about 100k (It's was that cracking head "feature" that the sohc 1.9L had about that era) It is a bit frustrating since I can't just run out to 29 palms from Michigan and give the car a good looking over.
On a bynote I have 2 more Saturns in my stable in adition to the 97 SC1. I run a 2002 SL2 and a 2004 V6 FWD Vue. I did a suspension overhaul on the 02 SL and dropped in a set of Urethane bushing on the car, which was a lot of fun. I can post pics of that if anyone wants to see what is involved.

The term just does not imply much of a time interval between pulling the thing out of storage and checking the gas miliage. Very few cars that I know of can recognise the difference between what state they are or have been in. However storage in the mohave area and sitting in my driveway in Phoenix might not be a whole bunch of difference. Hot and dry comes to mind. Mine pretty much sat there for about 3 years a few years back and once the transmission loosened up again (it shifted a bit harsh) you could not tell it had been basically parked. Gas mileage for an automatic could be in the 20ish area around town and not a whole lot over the 30ish area on the open road and be just fine. So what is the gas mileage. Also how much gas has been gone through? Gasoline formulation has changed and sitting around does not do a whole lot of good to the quality of the gasoline that is left in the tank. I started seeing some problems develop about 2 years ago with my cars that are not driven very much due to that. Mostly with the ones parked in the driveway which never have been bothered before.
If everything is recent and there are no driveability problems I would suggest running gasoline through the car a bit to flush the old gasoline out and get it out of the system, if there are driveability problems I suspect a stuck valve in the engine or some problem in the fuel metering system is possible which pretty much says that the tank needs to be pulled and cleaned and what is wrong found and fixed. But that is way to hard to guess at while typing on a key board with the amount of information given at the present.

I would expect the first tank of fuel to really "suck" maybe the "old gas" was all that is wrong. I say tune it then run it.

I haven't had a chance to hear about how the car is doing since the last post. I did mention to him that once he ran the old gas out it may help. Didn't thing about the tranny needing to loosen back up. I know he said he lost about 10 MPG. It was running mid to upper 30's and when he got back it was pushing around 25.
I will give an update when I get a chance to talk to him about the car.