Cadillac: 1990 Cadillac Sedan DeVille runs rough, cadillac sedan deville, fuel injector cleaner

Question
Car has 101000 miles, had tuneup at 100000, plugs wires etc. before tuneup car started running rough, put in fuel injector cleaner, cleared up. After tuneup car started running rough again at all speeds. I had disconnected the  battery for 2 months while I was in Florida and when reconnected again car ran fine for about 2 months. Car is only driven 30 miles (speed no higher than 40mph)a week. Car failed emissions, Carbon Monoxide was .94, all other parameters are well within spec.. If I disconnect battery for a couple of hours car runs fine for a while. It seems if I keep the speed low it runs OK, but if I get on highway (65mph) it starts running rough again. Any help will be appreciated.

Thanx
Stan

Answer
You do NOT want to disconnect the battery as it screws up all the sensor settings within the computers.

You need to perform a RE-LEARN procedure on the vehicle and DO NOT disconnect the battery any more. E-mail me at: onlineautohelp@msn.com for the procedure.