1998 Metro Idle Problem...HELP FAST!!

I am looking at a 1998 Chevy Metro the 1.3L type...4 door. When you first start it up it idles fine...you put it in gear and stop the idle jumps and slowly comes back down. Also when driving if you are easy on the gas it is fine but if you get on it hard it becomes hesitant...what would this be...the check engine light is on. Thanks

you need to take it to a napa or schucks and have them check codes to start with and see what it says the problem is

I bought the car...It seems as if it may have been in a flood. The manuals in the glove box are water damaged, there were pennies w/ corrosion, etc. I have drove it about 15 miles or so and it seems to get a little better. I took it to advanced and it threw a ton of codes. It will not take fuel...well it will slowly. If you fill it too fast it will spit it out. ANY SUGGESTIONS? PLEASE HELP> THIS IS NOW MY DAILY DRIVER!!!! Should I just keep driving it and try to clean it out? When I first started I had a hard time hitting 5 mph then I hit 25...now recently just 42 then had to slow down for a light. If I push the gas too much though it just boggs right down...I pretty much need to feather the gas up to speed!!!