1997 Galant 500RPM idle and stalling hour after ECU reset
 

Hey guys I'm just a teenager trying to figure out what is wrong with his moms car so please forgive me if the terminology is shot.

So my mom has her car, a Mit Galant 1997. It runs terrible, mashing the accelerator down barely makes the car go, and when it does, it sounds like the engine is having a seizure and immediately gains all the power missing. Physical car shaking, and the like.

Disconnecting the battery terminals and leaving it overnight will make the problem go away, about 3 miles is how far you get until the car becomes a deathtrap once more.

My question is, after an ECU reset, why is the car running fine and then learning to misfire, idle at 400 RPM and stall at red lights? The car is an automatic transmission.

When was the last time the car had a proper tune up? (Spark plugs, spark wires, distributor cap and rotor, oil change w/ new filter, new air filter, replace fuel filter)

From there you can start diagnosing.